Semiconductor device and method for manufacturing the same, and electric device

ABSTRACT

It is an object of the present invention to simplify steps needed to process a wiring in forming a multilayer wiring. In addition, when a droplet discharging technique or a nanoimprint technique is used to form a wiring in a contact hole having a comparatively long diameter, the wiring in accordance with the shape of the contact hole is formed, and the wiring portion of the contact hole is likely to have a depression compared with other portions. A penetrating opening is formed by irradiating a light-transmitting insulating film with laser light having high intensity and a pulse high in repetition frequency. A plurality of openings having a minute contact area is provided instead of forming one penetrating opening having a large contact area to have an even thickness of a wiring by reducing a partial depression and also to ensure contact resistance.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a semiconductor device having a circuitincluding a thin film transistor (hereinafter, referred to as a TFT) andto a manufacturing method thereof. Specifically, the present inventionrelates to a semiconductor device having a circuit including a fieldeffect transistor (hereinafter, referred to as an FET). For example, thepresent invention relates to an electronic device incorporating, as partthereof, a large-scale integrated circuit (LSI), an electro-optic devicetypified by a liquid crystal display panel, a light-emitting displaydevice having an organic light-emitting element, a sensor device such asa line sensor, or a memory device such as an SRAM or a DRAM, forexample.

2. Description of the Related Art

Note that a semiconductor device in this specification means generaldevices and apparatuses that can function with the use of semiconductorcharacteristics; for example, an electro-optical device, a semiconductorcircuit, and an electronic device are all included in a semiconductordevice.

In recent years, in the case of forming a multilayer wiring in asemiconductor element, irregularities are more significant in upperlayers, and the wirings are difficult to be processed. Correspondingly,a wiring material is generally embedded in a wiring opening such as awiring trench or a hole formed in an insulating film by a wiringformation technology called a damascene process.

A damascene process is a method in which a trench is first formed in aninsulating film, the entire surface is covered with a metal material(filling the trench), and the entire surface is polished by a CMP(chemical mechanical polishing) method or the like to form a metalwiring. The method further including a step of providing a hole below ametal wiring for contact with a metal wiring or a semiconductor regionin a lower wiring is called a dual damascene process. The dual damasceneprocess includes a step in which, after forming a hole for a connectionwith a lower layer wiring and a wiring trench are formed, a wiringmaterial is deposited, and the wiring material except the wiring portionis removed by a CMP method.

For a metal wiring using a dual damascene process, copper (Cu) by anelectroplating method is commonly used. In the electroplating method, aplating solution or the electric field to be applied is required to becontrolled intricately so that copper (Cu) is completely embedded in theconnection hole. In addition, it is difficult to process copper (Cu) byan etching process using an etchant or an etching gas; therefore, aspecial CMP method is required for polishing for copper (Cu) processing.

An electroplating method and a CMP method have had a problem of increasein manufacturing costs for forming a wiring.

In addition, not only in a manufacturing process of a semiconductordevice using a semiconductor substrate but also in a manufacturingprocess of an active matrix substrate using a thin film transistor(TFT), it is difficult to process a wiring in forming a multilayerwiring. In recent years, a thin film transistor is widely applied to anelectronic device such as an IC or an electro-optic device, and isparticularly developed as switching elements for image display devicesat a rapid rate. Note that a liquid crystal display device is generallywell known as an image display device.

An active matrix liquid crystal display device has often been usedbecause a high precision image can be obtained compared with a passiveliquid crystal display device. In the active matrix liquid crystaldisplay device, pixel electrodes arranged in matrix are driven todisplay an image pattern on the screen. Specifically, a voltage isapplied to a selected pixel electrode and an opposite electrodecorresponding to the pixel electrode, and thus, a liquid crystal layerbetween the pixel electrode and the opposite electrode is modulatedoptically. The optical modulation can be recognized as an image patternby an observer.

Application range of such an active matrix liquid crystal display deviceis expanding, and demands for the improvement of productivity and costreduction are increasing, as a display size gets larger.

Conventionally, in the case of forming a multilayer wiring, in order toconnect the upper wiring and the lower wiring, a contact hole is formedin an interlayer insulating film between these wirings by using aphotolithography method. In the case of forming a contact hole by usinga photolithography method, various steps such as forming a resist mask(coating, exposing, and developing a resist), etching selectively, orremoving a resist mask are necessary. In other words, it is necessary toform a contact hole to have a multilayer structure so that the pluralityof wirings cross to each other, which has been one of causes of increasein the number of manufacturing processes.

In addition, in the case of using a photolithography method, a photomaskis also necessary for each exposure pattern; therefore, a cost formanufacturing the photomask is increased, which has been one of causesof increase in a manufacturing cost.

Moreover, in the case of using a photolithography method, largequantities of resist materials and developing solutions are used inorder to improve uniformity; thus, a great deal of surplus materials isconsumed.

As for a method for etching an interlayer insulating film selectively,dry etching and wet etching are known. Generally, dry etching by gasplasma has an advantage in forming a pattern processed into a taperedshape or the like. However, a dry-etching apparatus is disadvantageousin that an expensive large-scaled apparatus is needed and amanufacturing cost is increased. In addition, there is a fear that asemiconductor element is damaged due to gas plasma. Therefore, it isdesirable that dry etching is performed as less as possible.

In addition, wet etching which is inexpensive and superior in terms ofmass production compared with dry etching uses a great deal of etchantonce; therefore, waste fluid treatment is difficult, which has been oneof causes of increase in a manufacturing cost. In addition, since wetetching is isotropic etching, it is difficult to form a contact holehaving comparatively small diameter, which is disadvantageous in highintegration of a circuit.

As for a method without using a photoresist in processing a thin film bypatterning, a laser-processing technique, particularly alaser-processing method using YAG laser light (wavelength of 1.06 μm) isknown. In the laser-processing method with the use of YAG laser light,as well as an object to be processed is irradiated with a spot-likebeam, the beam is scanned into a processing direction to form an openinginto a chain shape of continuous dots.

In addition, the present applicant uses laser light having a wavelengthof 400 μm or less to irradiate a light-transmitting conductive film witha linear beam. A method for processing a thin film for forming anopening is described in Reference 1: U.S. Pat. No. 4,861,964Specification, Reference 2: U.S. Pat. No. 5,708,252 Specification, andReference 3: U.S. Pat. No. 6,149,988 Specification.

SUMMARY OF THE INVENTION

It is an object of the present invention to simplify steps needed toprocess a wiring in forming a multilayer wiring. Further, it is anobject of the present invention to provide a technique to realize highintegration of a circuit.

In addition, in the case of forming a plurality of contact holesdifferent in depth, a process tends to be complicated. Consequently, thepresent invention provides a technique capable of realizing a pluralityof contact holes different in depth in a simplified process.

Moreover, in manufacturing an electronic device having a semiconductorcircuit, a gang printing that is a manufacturing method of cutting out aplurality of devices from one mother glass substrate for mass productionefficiently is employed without using a wafer substrate. The size of amother glass substrate is increased from 300 mm×400 mm of the firstgeneration in the early 1990s to 680 mm×880 mm or 730 mm×920 mm of thefourth generation in 2000. Further, the manufacturing technique has beendeveloped so that a large number of devices, typically, display panelscan be obtained from one substrate.

In forming a metal film to be a wiring by a deposition method with theuse of a sputtering method when the substrate size is further increasedhereafter, a target becomes expensive as the size is increased, which isdisadvantageous for mass production.

In addition, in consideration of mass production, it is also an objectof the present invention to provide a technique to form a wiringappropriate for a large-sized substrate.

According to the present invention, a light-transmitting insulating filmthat is formed to cover a conductive layer is selectively irradiatedwith laser light to form a penetrating opening that reaches theconductive layer. A step of forming a contact hole can be simplified byforming a penetrating opening in a light-transmitting insulating film bylaser light.

In addition, a focal position of laser light is appropriately determinedby a practitioner. Therefore, the depth of a penetrating opening or thesize of a penetrating opening can be decided appropriately. Thus,according to the present invention, a plurality of contact holesdifferent in depth can be realized in a simplified process. Moreover,the light-transmitting insulating film is not limited to a single layer,and a step of forming a contact hole can be simplified even in a stackedlayer of two or more layers.

According to laser light of the present invention, a fundamental wave isused without putting laser light into a non-linear optical element, anda penetrating opening is formed by irradiating a light-transmittinginsulating film with pulsed laser light having high intensity and a highrepetition rate. One feature of the present invention is that therepetition rate of laser used in the present invention is set to be 10MHz or more.

High intensity means a high peak output power per unit of time and perarea and the peak output power of laser light according to the presentinvention ranges from 1 GW/cm² to 1 TW/cm².

A fundamental wave with a wavelength of approximately 1 μm is notabsorbed so much by a light-transmitting insulating film in irradiatingthe light-transmitting insulating film with the fundamental wave. Thus,the fundamental wave has low absorption efficiency. A fundamental waveemitted from a pulsed laser having a pulse width in the range ofpicosecond or in the range of femtosecond (10⁻¹⁵ seconds) can providehigh intensity laser light. Thus, a non-linear optical effect(multi-photon absorption) is generated and the fundamental wave can beabsorbed by light-transmitting insulating film to form a penetratingopening.

Additionally, a shape of an opening in a plane perpendicular to asubstrate can be determined appropriately by a practitionerappropriately determining a focal position of laser light. For example,an opening the opening area on a surface of a light-transmittinginsulating film of which is smaller than an exposed area of a conductivelayer can be formed.

In a conventional processing method using YAG laser light, a beam shapeis circular and light intensity shows a Gaussian distribution;therefore, an opening shape in a plane perpendicular to a surface of anobject to be processed has a shape in accordance with a Gaussiandistribution. Thus, in the conventional processing method using YAGlaser light, an opening on a surface is likely to increase in size, andit is difficult to form a deep contact hole having a minute openingsize. In addition, a pulse width that is used in the conventionalprocessing method using YAG laser light is 10⁻⁴ second to 10⁻² second.

In addition, in a conventional processing method, where alight-transmitting conductive film is irradiated with a linear beam toform an opening with the use of laser light having a wavelength of 400μm or less, an opening is formed from the surface of thelight-transmitting conductive film because the light-transmittingconductive film that absorbs laser light having a wavelength of 400 μmor less is used. A surface easily absorbs energy also in this processingmethod; thus, an opening diameter on the surface gets longer easily.

Compared with the conventional processing method, a processing methodaccording to the present invention is not limited to forming an openingpenetrating from a surface, and various formation methods are available.For example, when a light-transmitting insulating film is irradiatedwith laser light while moving a focal position of the laser light from aconductive layer side to a surface, an opening penetrating from theconductive layer side to a surface is formed in the light-transmittinginsulating film. In addition, it is also possible to form an opening inan insulating film by being irradiated with laser light to penetratethrough a light-transmitting substrate from a backside, that is, thesubstrate side.

In addition, according to the present invention, an opening having acomplicated shape can also be formed by freely moving a focal positionof laser light. For example, an opening penetrating in a verticaldirection is formed in a Z direction (depth direction) and then a holein a lateral direction is formed in an X direction or a Y direction.

Further, it is also one feature of the present invention to use aprinting technique such as a droplet discharging technique typified by apiezo type and a thermal jet type or a nanoimprint technique to form awiring or an electrode in a position overlapped with an opening of aninsulating film and to electrically connect to a conductive layerthrough the opening of the insulating film.

For example, in the case of using a droplet discharging technique, aconductive material where a material solution is adjusted and droppedcan have fluidity; therefore, even an opening having a crookedcomplicated shape can be filled with the conductive material. Forexample, even a hole where the side wall is in a reverse tapered shapecan be filled with the conductive material. In addition, a deep openingor an opening having a complicated shape can be filled with theconductive material by making the most of speed of a conductive materialthat is dropped using a droplet discharging technique. Moreover, it isalso one feature of the present invention to provide an opening filledwith the conductive material having fluidity is easily filled.

In addition, in the case of using a printing technique such as ananoimprint technique, it is also possible to fill an opening having acomplicated shape by giving fluidity to the conductive material with aconductive material in performing heat treatment for baking.

Moreover, when a wiring is formed with the use of a droplet dischargingtechnique or a nanoimprint technique in a contact hole having acomparatively long diameter, for example, a diameter longer than 2 μm,the wiring in accordance with the shape of the contact hole is formed,and the wiring portion of the contact hole is likely to have adepression compared with other portions. FIGS. 19A to 19C each shows astate in which a conventional contact hole is formed. A base insulatingfilm 3011 is provided over a substrate 3010, and a conductive layer 3012is provided over the base insulating film 3011. In FIG. 19A, aninsulating film is formed over the conductive layer 3012, a resist mask3014 is formed by a photolithography technique, and an opening 3016 isformed by etching. Then, by removing the resist mask 3014 and forming awiring with the use of a droplet discharging technique or a nanoimprinttechnique, a wiring 3017 a as shown in FIG. 19B is formed. As shown inFIG. 19B, the wiring 3017 a is a wiring in accordance with the shape ofthe contact hole and the wiring portion of the contact hole has adepression compared with other portions. Further, when baking isperformed, the wiring 3017 a is transformed into a wiring 3017 b asshown in FIG. 19C because the wiring material has fluidity. Thus, thewiring material moves to a material movement direction 3018 shown in anarrow in FIG. 19C and there is a fear that the thickness of the wiringin vicinity of the contact hole becomes thinner compared with otherportions. In addition, in the case of using a material having lowviscosity and fluidity in a droplet discharging technique, the materialof a wiring tends to move to a lower place before baking, that is, justafter forming the wiring.

Thus, it is also one feature of the present invention to provide aplurality of openings having a minute contact area the diameter of whichis 2 μm or less, preferably approximately 3 nm to 200 nm, instead offorming one penetrating opening having a large contact area to have aneven thickness of a wiring by reducing a partial depression and also toensure contact resistance.

According to one feature of the present invention disclosed in thisspecification, the example of which is shown in FIG. 1C, a semiconductordevice comprises a first conductive layer; a plurality of penetratingopenings (also referred to as a plurality of openings); an insulatingfilm covering the first conductive layer; and a second conductive layerin contact with the first conductive layer through the plurality ofpenetrating openings, wherein the second conductive layer containsconductive particles, and wherein a surface of the second conductivelayer which is overlapped with the plurality of penetrating openings anda surface of the second conductive layer which is not overlapped withthe plurality of penetrating openings are formed in one side. In otherwords, the second conductive layer is leveled. The width of the secondconductive layer D and a diameter of each of the plurality of openings Wsatisfy 2D<W.

In addition, according to the above feature, the second conductive layerhas a plurality of crystals where the conductive particles are assembledand the crystals are overlapped. When a wiring is formed with aconductive material containing metal particles of 3 nm to 7 nm in sizeby a droplet discharging method or a printing method and is baked, themetal particles are dissolved and assembled to have an approximately 100nm crystal, which is formed to irregularly overlap in three dimensions.

According to another feature of the present invention, a diameter of apenetrating opening is longer than one conductive particle. The openinghas a diameter longer than a diameter of the metal particles to be used(3 nm to 7 nm) so that at least the metal particles enter the opening onthe surface. Specifically, a diameter of a penetrating opening accordingto the present invention is 3 nm to 2000 nm.

In addition, the present invention is not limited to the opening incontact with the lower conductive layer. According to another feature ofthe present invention, a semiconductor device comprises a semiconductorlayer, a plurality of penetrating openings; an insulating film coveringthe semiconductor layer; and a conductive layer in contact with thesemiconductor layer through the plurality of penetrating openings,wherein the conductive layer contains conductive particles, and whereina surface of the conductive layer which is overlapped with the pluralityof penetrating openings and a surface of the conductive layer which isnot overlapped with the plurality of penetrating openings are formed inone side.

In addition, according to the present invention, a shape of thepenetrating opening is not limited to a columnar shape having the samediameter, and a diameter of a cross section taken along a horizontalplane may be partially different. For example, a diameter of an openingin a bottom surface of a insulating film may be ten or more times aslong as a diameter of an opening in a top surface of the insulatingfilm, as long as the diameter of the opening in the top surface of theinsulating film is longer than a metal particle. In addition, a crosssection taken along a horizontal plane of the penetrating opening is notlimited to a circle and may also be elliptical or rectangular. When across section taken along a horizontal plane of the penetrating openingis elliptical, the length of a minor axis preferably ranges from 3 nm to2000 nm. When a cross section taken along a horizontal plane of thepenetrating opening is rectangular, the length of a narrow sidepreferably ranges from 3 nm to 2000 nm.

In addition, in order to lower electric resistance, a diameter of anopening in a bottom surface of an insulating film may be the same or maybe longer than a diameter of one crystal so that a crystal made ofassembled metal particles is formed even in the opening.

Since an opening shape according to the present invention is formed bylaser light, the shape can be complicated. According to another featureof the present invention, a semiconductor device comprises a firstconductive layer; a plurality of penetrating openings; an insulatingfilm covering the first conductive layer, and a second conductive layerin contact with the first conductive layer through the plurality ofpenetrating openings, wherein the second conductive layer containsconductive particles, and wherein at least two penetrating openingsamong the plurality of penetrating openings are connected to each otherin the insulating film.

In addition, an opening shape according to the present invention is notlimited to a columnar shape extended to a direction of a film thickness(that is, a Z direction). According to the other feature of the presentinvention, a semiconductor device comprises a first conductive layer; aplurality of penetrating openings; an insulating film covering the firstconductive layer; and a second conductive layer in contact with thefirst conductive layer through the plurality of penetrating openings,wherein the second conductive layer contains conductive particles, andwherein a cross-sectional shape of the plurality of penetrating openingsis an L shape, a U shape, or a shape drawing an arc.

In addition, according to the present invention, a penetrating openingrefers to a passage leading to upper and lower layers sandwiching aninsulating film and a passage extended to a horizontal direction in theinsulating film. For example, a cross-sectional shape of the penetratingopenings according to the present invention includes an L shape, a Ushape, a shape drawing an arc, or the like. Even in the case of theopenings having such a complicated cross-sectional shape, the openinghaving a complicated shape can be filled with a conductive material byadjusting viscosity of the discharging material as long as a dropletdischarging method is used.

For example, according to the present invention, a plurality of minuteopenings can be connected to each other in a plane in contact with aconductive layer. Accordingly, a plurality of minute openings can beprovided to a top surface of an insulating film and a contact area canbe increased by connecting a plurality of openings with holes in alateral direction (holes extended to an X direction or a Y direction)provided in vicinity of a bottom surface of the insulating film. Inaddition, a plurality of vertical holes (holes extended to a Zdirection) is connected to horizontal holes (holes extended to an Xdirection or a Y direction) taken along a bottom surface of theinsulating film; therefore, an air escapeway can be provided indischarging droplets and thus air bubbles can be prevented fromremaining in the openings.

In addition, according to the above each feature, the semiconductordevice includes at least one of an antenna, a CPU (a central processingunit), and a memory. For example, according to the present invention,high integration of an integrated circuit having a multilayer wiringformed through penetrating openings can be realized. Specifically, anintegrated circuit having an antenna and a memory for identification andmanagement of goods, merchandise, and people, typically a wireless chip(also referred to as an ID tag, an IC tag, an IC chip, an RF (RadioFrequency) tag, a wireless tag, an electronic tag, or RFID (RadioFrequency Identification)) can be completed.

In addition, according to the above each feature, the semiconductordevice is a display device (an LCD panel or an EL panel), a videocamera, a digital camera, a personal computer, or a portable informationterminal. For example, according to the present invention, an integratedcircuit having a multilayer wiring formed through penetrating openingscan be manufactured in a simplified process; thus, an electronic deviceprovided with the integrated circuit can be completed.

In addition, according to one feature of a manufacturing method of thepresent invention to realize the above each feature, a method formanufacturing a semiconductor device comprises the steps of forming afirst conductive layer; forming an insulating film over the firstconductive layer; forming a plurality of penetrating openings in theinsulating film by being selectively irradiated with laser light; andforming a second conductive layer in contact with the first conductivelayer through the plurality of penetrating openings by a dropletdischarging method or a printing method.

In addition, according to the above feature of the manufacturing method,the step of forming the second conductive layer includes heat treatmentin which a surface of the second conductive layer which is overlappedwith the plurality of penetrating openings and a surface of the secondconductive layer which is not overlapped with the plurality ofpenetrating openings are formed in one side.

In addition, according to another feature of a manufacturing method ofthe present invention, a method for manufacturing a semiconductor devicecomprises the steps of forming a first conductive layer; forming aninsulating film over the first conductive layer; forming a plurality ofpenetrating openings different in depth in the insulating film by beingselectively irradiated with laser light; and forming a second conductivelayer that fills the plurality of penetrating openings by a dropletdischarging method or a printing method.

In addition, according to another feature of a manufacturing method ofthe present invention, a method for manufacturing a semiconductor devicecomprises the steps of forming a first conductive layer; forming aninsulating film over the first conductive layer; forming a plurality ofpenetrating openings different in depth in the insulating film by beingselectively irradiated with laser light; and forming a second conductivelayer by filling the plurality of penetrating openings with conductiveparticles after discharging a liquid material having the conductiveparticles into the plurality of penetrating openings by a dropletdischarging method.

In addition, according to each feature of the above manufacturingmethods, the plurality of penetrating openings is formed by moving afocal position of laser light to an X direction, a Y direction, or a Zdirection.

Since the plurality of penetrating openings is formed by moving a focalposition of laser light, various openings can be formed. According toeach feature of the above manufacturing methods, a cross-sectional shapeof the plurality of the penetrating openings is a columnar shape, an Lshape, a U shape, or a shape drawing an arc.

In addition, penetrating openings may be formed by forming a closed pore(a pore extended to a Z direction) in a light-transmitting insulatingfilm by laser light in advance to subsequently remove a surface layer byetching or rubbing.

According to another feature of a manufacturing method of the presentinvention, a method for manufacturing a semiconductor device comprisesthe steps of forming a first conductive layer; forming an insulatingfilm over the first conductive layer, forming a closed pore in contactwith the first conductive layer in the insulating film by beingselectively irradiated with laser light; forming the closed pore into apenetrating opening simultaneously with performing thin film process tothe insulating film; and forming a second conductive layer in contactwith the first conductive layer through the plurality of penetratingopenings by a droplet discharging method or a printing method. In otherwords, a manufacturing method of the present invention, a method formanufacturing a semiconductor device comprises the steps of forming afirst conductive layer on a substrate; forming an insulating film on thefirst conductive layer; forming a plurality of pores in the insulatingfilm by being selectively irradiated with laser light; removing upperregions of the insulating film of the plurality of pores to form aplurality of openings; and forming a second conductive layer in contactwith the first conductive layer though the plurality of openings by adroplet discharging method or a printing method.

In addition, according to each feature of the above manufacturingmethods, a diameter of the penetrating openings is 3 nm to 2000 nm.

In addition, a method for manufacturing a semiconductor device having atransistor using a semiconductor substrate is also one feature of thepresent invention. According to the feature, the method formanufacturing a semiconductor device having a transistor comprises thesteps of forming a first insulating film over a semiconductor substrate;forming a second insulating film over the first insulating film; forminga first penetrating opening that reaches the first insulating film and asecond penetrating opening that reaches the semiconductor substrate inthe second insulating film by being selectively irradiated with laserlight; and forming a gate electrode in contact with the first insulatingfilm through the first penetrating opening and an electrode in contactwith the semiconductor substrate through the second penetrating openingby a droplet discharging method.

In addition, a method for manufacturing a top gate thin film transistor(TFT) formed over a substrate having an insulating surface is also onefeature of the present invention. According to the feature, the methodfor manufacturing a semiconductor device, having a thin film transistor,comprises the steps of forming a semiconductor layer over a substratehaving an insulating surface; forming a first insulating film coveringthe semiconductor layer in the second insulating film by beingselectively irradiated with laser light; forming a second insulatingfilm; forming a first penetrating opening that reaches the firstinsulating film and a second penetrating opening that reaches thesemiconductor layer; and forming a gate electrode in contact with thefirst insulating film through the first penetrating opening and anelectrode in contact with the semiconductor layer through the secondpenetrating opening by a droplet discharging method.

Note that the first insulating film is a gate insulating film. Inaddition, the second insulating film is an interlayer insulating film.

In addition, a method for manufacturing a bottom gate thin filmtransistor (TFT) formed over a substrate having an insulating surface isalso one feature of the present invention. According to the feature, themethod for manufacturing a semiconductor device, having a thin filmtransistor, comprises the steps of forming a first insulating film overa substrate having an insulating surface; forming a semiconductor layerover the first insulating film; forming a second insulating film abovethe semiconductor layer; forming a first penetrating opening in thefirst insulating film and the second insulating film and a secondpenetrating opening that reaches the semiconductor layer in the secondinsulating film by being selectively irradiated with laser light; andforming a gate electrode through the first penetrating opening and anelectrode in contact with the semiconductor layer through the secondpenetrating opening by a droplet discharging method, wherein part of thefirst penetrating opening is formed below the semiconductor layer, andwherein the first insulating film between the first penetrating openingand the semiconductor layer is a gate insulating film. In other words, amethod for manufacturing a semiconductor device comprises the steps offorming a first insulating film on a substrate; forming a semiconductorlayer on the first insulating film; forming a second insulating film onthe semiconductor layer; forming a pore in the first insulating film andan opening that reaches the semiconductor layer in the second insulatingfilm by being selectively irradiated with laser light; and forming agate electrode through the pore and an electrode in contact with thesemiconductor layer through the opening by a droplet discharging methodor a printing method.

According to the above feature of the manufacturing method, the firstpenetrating opening is formed by laser light irradiation from the sideof the substrate having an insulating surface or by laser lightirradiation from the side of the second insulating film.

In addition, according to the above feature of the manufacturing method,the second insulating film is an interlayer insulating film.

In addition, according to the above feature of the manufacturing method,the first penetrating opening is an opening in which an opening in a Zdirection and an opening in an X direction or a Y direction areconnected. According to the above manufacturing method of the presentinvention, the second insulating film is formed first, and then, anopening like a tunnel is formed by laser light and the opening is filledwith a conductive material to form a gate electrode. Since the positionof the gate electrode in a depth direction can be set arbitrarily withthe use of laser light, it is also possible to obtain a thin film of thegate insulating film. Moreover, the gate electrode can also be formedwithout damaging the gate insulating film.

In addition, according to the above feature of the manufacturing method,a diameter of the first penetrating opening is 3 nm or more and 2000 nmor less.

In addition, according to each feature of the manufacturing method, thelaser light oscillates when a pulse width of the laser light is 1femtosecond or more and 10 picoseconds or less. High intensitymultiphoton absorption can occur can be obtained by having the pulsewidth in the range of 1 femtosecond or more and 10 picoseconds or less.Multiphoton absorption does not occur when a laser beam has a pulsewidth of several tens picoseconds longer than 10 picoseconds. Moreover,the laser light has a fundamental wave emitted from a laser oscillatorthe laser repetition frequency of which is 10 MHz or more.

In addition, according to the present invention, a semiconductor filmcontaining silicon as its main component, a semiconductor filmcontaining an organic material as its main component, or a semiconductorfilm containing metal oxide as its main component can be used for asemiconductor layer. As for the semiconductor film containing silicon asits main component, an amorphous semiconductor film, a semiconductorfilm including a crystalline structure, a compound semiconductor filmincluding an amorphous structure, or the like, specifically amorphoussilicon, microcrystalline silicon, polycrystalline silicon, singlecrystal silicon, or the like can be used. As for the semiconductor filmcontaining an organic material as its main component, a semiconductorfilm containing as its main component a material comprising carbon orallotropes (aside from a diamond) of carbon at a quantity, at leasthaving a material which has charge carrier mobility of 10⁻³ cm²/V·s ormore in room temperature (20° C.), can be used by being combined withother elements. For example, an aromatic of π electron conjugate system,a chain compound, an organic, or an organosilicon compound can be used.Specifically, pentacene, tetracene, thiophen oligomers, phenylenes, aphthalocyanine compound, poly acetylenes, polythiophenes, a cyanine dye,and the like are given as examples. As for the semiconductor filmcontaining metal oxide as its main component, zinc oxide (ZnO); oxide ofzinc, gallium, and indium (In—Ga—Zn—O); or the like can be used.

In addition, a semiconductor device according to the present inventionmay be provided with a protective circuit (for example, a protectiondiode) for preventing electrostatic discharge damage.

In addition, regardless of a TFT structure and a transistor structure,the present invention can be applied and, for example, a top gate TFT, abottom gate (reverse stagger) TFT, or a forward stagger TFT can be used.Moreover, not limiting to a transistor having a single gate structure, amulti-gate transistor having a plurality of channel-forming regions, forexample, a double gate transistor may be used.

According to the present invention, steps needed to process a wiring informing a multilayer wiring can be simplified. Further, high integrationof a circuit can also be realized.

In addition, a plurality of contact holes different in depth can berealized in a simplified process.

In addition, since a fundamental wave the wavelength of which isapproximately 1 μm is used according to the present invention, a contacthole can be formed without damaging an element and a substrate becausethe fundamental wave is not absorbed by the element and substrate.Therefore, a semiconductor device can be manufactured by using anelement that is easily affected by heat or an etching solution or a filmsubstrate that is easily affected by heat or an etching solution.

These and other objects, features and advantages of the presentinvention will become more apparent upon reading of the followingdetailed description along with the accompanied drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings:

FIGS. 1A to 1D are process cross-sectional views and a top viewaccording to the present invention (Embodiment Mode 1);

FIGS. 2A and 2B are cross-sectional views explaining a manufacturingprocess of an opening according to the present invention (EmbodimentMode 1);

FIGS. 3A to 3C are cross-sectional views and a top view showing oneexample of an opening shape according to the present invention(Embodiment Mode 2);

FIGS. 4A to 4C are cross-sectional views explaining a manufacturingprocess of an opening according to the present invention (EmbodimentMode 3);

FIGS. 5A to 5C are cross-sectional views and a top view showing oneexample of an opening shape according to the present invention(Embodiment Mode 4);

FIGS. 6A to 6D are cross-sectional views showing a manufacturing processof a bottom gate TFT (Embodiment Mode 5);

FIGS. 7A to 7D are cross-sectional views showing a manufacturing processof a top gate TFT (Embodiment Mode 6);

FIG. 8 is a cross-sectional view showing a structure of an active matrixliquid crystal display device (Embodiment Mode 6);

FIG. 9 is a cross-sectional view showing a structure of an active matrixEL display device (Embodiment Mode 6);

FIG. 10 is a diagram explaining a laser beam direct writing systemapplicable to the present invention (Embodiment Mode 1);

FIG. 11 is a diagram explaining a droplet discharging device applicableto the present invention (Embodiment Mode 1);

FIGS. 12A to 12D are cross-sectional views showing a method formanufacturing a semiconductor device (Embodiment 1);

FIG. 13 is a perspective view of a semiconductor device (Embodiment 1);

FIG. 14 is a top view showing a module (Embodiment 2);

FIGS. 15A and 15B are a block diagram and a perspective view of atelevision device (Embodiment 4);

FIGS. 16A to 16E are views each showing one example of an electronicdevice (Embodiment 5);

FIG. 17 is one example of a cross-sectional view showing a structureaccording to the present invention (Embodiment 6);

FIGS. 18A to 18F are perspective views explaining application examplesof a semiconductor device (Embodiment 6); and

FIGS. 19A to 19C are cross-sectional views showing a conventionalexample.

DETAILED DESCRIPTION OF THE INVENTION

Embodiment Mode of the present invention will be described below withreference to the accompanying drawings. However, it is to be easilyunderstood that various changes and modifications will be apparent tothose skilled in the art. Therefore, unless such changes andmodifications depart from the invention, they should be construed asbeing included therein. Note that reference numerals denoting theidentical portions are the same in all figures.

Embodiment Mode 1

In this embodiment mode, a method for forming a contact hole in a firstconductive layer and a method for forming a second conductive layerelectrically connected to the first conductive layer through the contacthole will be explained with reference to FIGS. 1A to 1D, FIGS. 2A and2B, FIG. 10, and FIG. 11.

First, a base insulating film 11 is formed over a substrate 10 having aninsulating surface, and a first conductive layer 12 is formed over thebase insulating film 11. Next, an insulating film 13 covering the firstconductive layer 12 is formed. A cross-sectional view of this stage isshown in FIG. 1A.

Note that a glass substrate or quartz substrate having lighttransparency is preferably used as the substrate 10 having an insulatingsurface.

In addition, as for the base insulating film 11, a base film made of aninsulating film such as a silicon oxide film, a silicon nitride film, ora silicon oxynitride film is formed. Herein, an example where atwo-layer structure is used as a base film is shown; however, theinsulating film may be a single layer film or may have a structure wheretwo or more layers are stacked. Note that the base insulating film isnot particularly necessary.

In addition, as for the first conductive layer 12, a conductive film 100nm to 600 nm in thickness is formed by a sputtering method and thenpatterning is performed with the use of a photolithography technique.Note that the conductive film is formed of one or more elements of Ta,W, Ti, Mo, Al, Cu, and Si, or a single layer or a stacked layer of analloy material or a compound material containing the element as its maincomponent. Herein, an example where the first conductive layer is formedwith the use of a photolithography technique is shown; however, thefirst conductive layer 12 may be formed by droplet discharging method, aprinting method, or electroless plating without being particularlylimited. It is preferable for the first conductive layer 12 to use amaterial that reflects and hardly absorbs laser light used in thesubsequent opening process.

Moreover, the first conductive layer 12 may also be formed using atransparent conductive material such as ITO, IZO, or ITSO. It ispreferable to use a material that transmits and hardly absorbs laserlight used in the subsequent opening process.

In addition, the insulating film 13 is formed using an insulatingmaterial that transmits and hardly absorbs laser light used in thesubsequent opening process, for example, an insulating film such as asilicon oxide film, a silicon nitride film, or a silicon oxynitridefilm. Moreover, the insulating film 13 may be formed using an insulatingfilm where a framework structure is formed by the bond between silicon(Si) and oxygen (O), which is obtained by a coating method. Further, asfor the insulating film 13, the following can also be used: PSG(phosphosilicate glass) in which phosphorus is added to silicon dioxide;BPSG (borophosphosilicate glass) in which phosphorus and boron are addedto silicon dioxide; SiOF in which fluorine is added to silicon dioxide;polyimide; aromatic ether typified by polyfluoroether in whichpolyallylether or fluorine is added; aromatic hydrocarbon; a cyclobutanederivative typified by BCB (Benzocyclobutene); or the like.

Although a planar insulating film is shown as the insulating film 13 inFIG. 1A, an inorganic insulating film obtained by a CVD method or asputtering method may be used without being particularly limited. Aplurality of openings can be formed using laser light according to thepresent invention even when the insulating film 13 does not haveplanarity.

In this embodiment mode, the insulating film 13 is formed by performingdrying and baking after coating or discharging the material with the useof a coating method or a droplet discharging method.

Next, the insulating film 13 is irradiated with laser light to form aplurality of penetrating openings as shown in FIG. 1B. Herein, laserlight emitted from an ultrashort pulsed laser is used as the laserlight. When an ultrashort pulsed laser is condensed in alight-transmitting material, multiphoton absorption can occur only at acondensed spot where the ultrashort pulsed laser is condensed, a closedpore can be formed, and one penetrating opening can be formed by movingthe condensed spot. When the pulsed width of the laser light is 10⁻⁴seconds to 10⁻² seconds, the laser light is not absorbed by theinsulating film 13. However, when multiphoton absorption occurs byirradiating the insulating film 13 with laser light the pulse width ofwhich is extremely short (picoseconds (10⁻¹² seconds) or femtoseconds(10⁻¹⁶ seconds)), the laser light can be absorbed by the insulating film13.

An ultrashort pulsed laser oscillator 101 is a laser oscillator with apulse width of femtoseconds (10⁻¹⁵ seconds). The ultrashort pulsed laseroscillator 101 may be a laser having a medium of a crystal of sapphire,YAG, ceramic YAG, ceramic Y₂O₃, KGW (potassium gadolinium tungsten),Mg₂SiO₄, YLF, YVO₄, GdVO₄, or the like, each of which is doped with oneor a plurality of Nd, Yb, Cr, Ti, Ho, and Er. Laser light emitted fromthe ultrashort pulsed laser oscillator 101 is reflected by a mirror 102,and then condensed in a sample 104, herein the insulating film 13provided over the substrate, by an objective lens 15 with a highnumerical aperture (see FIG. 2A). As a result, a pore can be formed inthe vicinity of a condensed spot in the insulating film. A desiredopening is formed in the insulating film 13 by moving the condensed spotwith the use of an XYZ stage 105. FIG. 2B shows a cross-sectional viewin the middle of forming an opening. A non-penetrating opening is shownin FIG. 2B as a pore 17.

Note that an ultrashort pulsed laser in this specification is a laserbeam oscillated from a solid-state laser where a pulse width is 1femtosecond or more and 10 picoseconds or less. Note that a peak powerof laser light according to the present invention ranges from 1 GW/cm²to 1 TW/cm².

The ultrashort pulsed laser allows processing to be performed only atthe beam center with high energy density; therefore, fine processing,that is, a laser wavelength or less can be processed using theultrashort pulsed laser having a laser wavelength or less that is noteasily processed by a normal laser.

The insulating film 13 needs to be formed using a material thattransmits light having the wavelength of the ultrashort pulsed laser,namely, a material in which light having the wavelength of theultrashort pulsed laser is not absorbed, and more specifically, amaterial having a higher energy gap than the ultrashort pulsed laser.When the ultrashort pulsed laser is condensed in the material thattransmits light, multiphoton absorption can occur only at a condensedspot where the ultrashort pulsed laser is condensed and a pore can beformed. Note that the multiphoton absorption is a process where two ormore photons are absorbed concurrently to make a transition to aneigenstate that corresponds to the sum of energy of the photons. Thistransition allows light in a wavelength range that is not absorbed to beabsorbed; therefore, a pore can be formed in a condensed spot having asufficiently high light energy density. Note that the term“concurrently” herein referred means that two phenomena occur within10⁻¹⁴ seconds.

A laser beam direct writing system is described with reference to FIG.10. As shown in FIG. 10, a laser beam direct writing system 1001 has apersonal computer (hereinafter referred to as a PC) 1002 for carryingout various controls in irradiation of a laser beam; a laser oscillator1003 for outputting a laser beam; a power supply 1004 of the laseroscillator 1003; an optical system (ND) filter) 1005 for attenuating alaser beam; an acousto-optic modulator (AOM) 1006 for modulating theintensity of a laser beam; an optical system 1007 constituted by a lensfor magnifying or reducing the cross-sectional surface of a laser beam,a mirror for changing the optical path, and the like; a substrate movingmechanism 1009 having an X stage and a Y stage; a D/A converter portion1010 for digital-analog converting the control data outputted from thePC; a driver 1011 for controlling the acousto-optic modulator 1006 inaccordance with an analog voltage outputted from the D/A converterportion; and a driver 1012 for outputting a driving signal for drivingthe substrate moving mechanism 1009.

The laser oscillator 1003 is a laser oscillator with a pulse width offemtoseconds (10⁻¹⁵ seconds).

Next, a method for irradiating a laser beam using the laser beam directwriting system will be explained. When a substrate 1008 is placed on thesubstrate moving mechanism 1009, the PC 1002 detects the position of amarker formed on the substrate by using a camera (not shown). Then, thePC 1002 generates movement data for moving the substrate movingmechanism 1009 in accordance with the detected positional data of themarker and the preprogrammed writing pattern data. Subsequently, the PC1002 controls the amount of light outputted from the acousto-opticmodulator 1006 through the driver 1011; therefore, and a laser beamoutputted from the laser oscillator 1003 is attenuated by the opticalsystem 1005 and then controlled in quantity by the acousto-opticmodulator 1006 to have a predetermined quantity of light.

Meanwhile, the optical path and beam shape of the laser beam outputtedfrom the acousto-optic modulator 1006 is changed by the optical system1007 and the laser beam is condensed by the lens. Then, an insulatingfilm over the substrate is irradiated with the laser beam to form apore. At this time, the substrate moving mechanism 1009 is controlled tomove in the Z direction in accordance with the movement data generatedby the PC 1002. As a result, a predetermined area is irradiated with thelaser beam, and the pore is connected to the Z direction to form anopening in the insulating film. When the substrate moving mechanism 1009is controlled to move in the X direction and the Y direction, a pore isformed in the insulating film in a direction horizontal to the substrateplane.

A laser beam with a shorter wavelength can be condensed to have ashorter diameter of beam. Accordingly, an opening with small diametercan be formed by irradiation of a laser beam with a short wavelength.

The laser beam spot on the surface of the pattern can be processed bythe optical system so as to have a dotted shape, a circular shape, anelliptical shape, a rectangular shape, or a linear shape (to be exact,elongated rectangular shape).

Although, herein, the substrate is selectively irradiated with the laserbeam while being moved, the present invention is not limited to this andthe substrate can be irradiated with the laser beam while scanning thelaser beam in the Z direction, X direction, and Y direction. In thiscase, a polygon mirror, a galvanometer mirror, or an acousto-opticdeflector (AOD) is preferably used for the optical system 1007.

Subsequently, a second conductive layer 19 is formed by discharging acomposition containing conductive particles by a droplet dischargingmethod so that a plurality of penetrating openings 16 is overlapped (seeFIG. 1C). The second conductive layer 19 is formed using a dropletdischarging means 18. The droplet discharging means 18 is a collectiveterm of means for discharging a droplet, such as a nozzle having anoutlet of a composition, and a head having one or more nozzles. Thedroplet discharging means 18 has a nozzle with a diameter of 0.02 μm to100 μm (preferably, 30 μm or less), and the discharge amount of acomposition discharged from the nozzle is 0.001 pl to 100 pl(preferably, 10 pl or less). The discharge amount increases inproportion to the diameter of the nozzle. The distance between an objectand the outlet of the nozzle is preferably as short as possible, andreduced to approximately 0.1 mm to 3 mm (preferably, 1 mm or less) inorder to discharge the composition onto a desired area.

As for the composition discharged from the outlet, a solution whereconductive particles are dissolved or dispersed in a solvent is used.The conductive particles may be a metal such as Ag, Au, Cu, Ni, Pt, Pd,Ir, Rh, W, and Al; a metal sulfide such as Cd and Zn; an oxide such asFe, Ti, Si, Ge, Zr, and Ba; fine particles such as silver halideparticles; or dispersed nanoparticles. However, the compositiondischarged from the outlet is preferably a solution where gold, silver,or copper is dissolved or dispersed in a solvent in view of theresistivity. More preferably, silver or copper that has low resistanceis used. Note that if silver or copper is used, a barrier film ispreferably provided for preventing impurities from entering. As for thesolvent, esters such as butyl acetate and ethyl acetate, alcohols suchas isopropyl alcohol and ethyl alcohol, or an organic solvent such asmethyl ethyl ketone and acetone may be used. The viscosity of thecomposition is preferably 50 cp or less for preventing drying and forallowing the composition to be discharged, smoothly from the outlet. Thesurface tension of the composition is preferably 40 mN/m or less.However, the viscosity and the like of the composition may be setappropriately in accordance with the solvent or the application.

It is preferable that the diameter of the conductive particles is assmall as possible in order to prevent each nozzle from clogging or tomake fine patterns, and more preferably, each particle has a diameter of0.1 μm or less, though it depends on the diameter of each nozzle or thedesired pattern shape. The composition is formed by a known method suchas an electrolytic method, an atomization method, and wet reduction, andthe particle size is generally approximately 0.01 μm to 10 μm. Note thatif the composition is formed by a gas evaporation method, nanoparticlesprotected with a dispersant are as fine as approximately 7 nm, and thenanoparticles are dispersed stably at room temperature and behavesimilarly to liquid without aggregation in a solvent when each of themis protected with a coating. Therefore, it is preferable to use acoating.

Here, a droplet discharging device will be explained with reference toFIG. 11. As the each heads 1105 and 1112 of the droplet dischargingmeans is connected to control means 1107 and the control means 1107 iscontrolled by a computer 1110, a pattern that has been programmed inadvance can be plotted. The timing of plotting may be taken withreference to a marker 1111 formed over a substrate 1100, for example.Alternatively, a reference point may be fixed with an edge of thesubstrate 1100 as a reference. The reference point is detected by animaging means 1104 such as an image sensor using a charge coupled device(CCD) or a complementary metal-oxide semiconductor (CMOS), and thecomputer 1110 recognizes a digital signal converted by an imageprocessing means 1109 to generate a control signal, which is transmittedto a control means 1107. Of course, information of a pattern to beformed over the substrate 1100 is placed in a recording medium 1108.Based on this information, the control signal can be transmitted to thecontrol means 1107 and each head 1105 and 1112 of the dropletdischarging means 1103 can be controlled individually. A material to bedischarged is supplied to the heads 1105 and 1112 from material supplysources 1113 and 1114 through a piping. Although the longitudinal lengthof the heads 1105 and 1112 arranged in parallel of the dropletdischarging means 1103 corresponds to the width of the substrate in FIG.11, the droplet discharging device can form a pattern over a large-sizedsubstrate wider than the longitudinal length of the heads 1105 and 1112by scanning the heads repeatedly. In that case, the heads 1105 and 1112can be scanned freely over the substrate in directions denoted by arrowsso that a region to be written can be freely set. Accordingly, aplurality of same patterns can be written over a substrate.

Next, as well as baking and removing the wiring material by beingirradiated with laser light or by heat treatment, any one or a pluralityof reaction of fusing, sintering, and welding of conductive particles isperformed.

In addition, FIG. 1D shows one example of a top view showing afterforming the second conductive layer 19. Note that FIG. 1C corresponds toa cross-sectional view taken along a broken line A-B in FIG. 1D.

As shown in FIG. 1D, a number of penetrating openings (herein, 10penetrating openings) are provided, and the second conductive layer 19is electrically connected to the first conductive layer 12 through theopenings. Note that the number of the openings is not limited to ten, ofcourse, and disposition of the openings is not particularly limited.

In addition, an insulator between the minute penetrating openings 16serves as a spacer, which prevents a surface of the second conductivelayer from generating a depression. The second conductive layer 19 canhave a uniform wiring width. A width of the second conductive layer Dand a diameter of each of the plurality of penetrating openings Wsatisfy 2D<W (FIG. 1D).

Embodiment Mode 2

In this embodiment mode, an example of an opening the cross-sectionalshape of which differs from Embodiment Mode 1 will be shown withreference to FIGS. 3A to 3C. Portions different from Embodiment Mode 1will be explained in detail and portions identical with FIGS. 1A to 1Din FIGS. 3A to 3C are denoted by the same reference numerals.

Note that a cross-sectional shape of an opening in FIGS. 1A to 1D isshown in a columnar shape; however, the present invention is not limitedthereto and an opening the shape of which has a structure in which aplurality of openings is connected to each other in an insulating filmas shown in FIG. 3 may be employed.

First, as well as in Embodiment Mode 1, a base insulating film 11 and afirst conductive layer 12 are formed over a substrate 10 having aninsulating surface.

Next, after forming an insulating film made of a material that is lighttransmitting to laser light having a pulse width of 10⁻⁴ seconds to 10⁻²seconds, an insulating film 23 having a penetrating opening 26 isobtained by irradiation of ultrashort pulsed laser light. When anultrashort pulsed laser is condensed in an insulating film, multiphotonabsorption can occur only at a condensed spot where the ultrashortpulsed laser is condensed, a closed pore can be formed, and onepenetrating opening can be formed by moving the condensed spot. When thepulsed width of the laser light is 10⁻⁴ seconds to 10⁻² seconds, thelaser light is not absorbed by the insulating film 23. However, whenmultiphoton absorption occurs by irradiating the insulating film 23 withlaser light the pulse width of which is extremely short (picoseconds orfemtoseconds), the laser light can be absorbed by the insulating film23.

Note that forming an opening by using laser light is explained in detailin Embodiment Mode 1; therefore, only brief explanation is given here.

The opening 26 having a complicated cross-sectional shape as shown inFIG. 3A can be formed by moving a focal position of laser light to a Zdirection, an X direction or a Y direction during laser lightirradiation.

Next, a second conductive layer 29 is formed by discharging acomposition containing conductive particles so as to overlap with theopening 26 with the use of a droplet discharging method (see FIG. 3B).The second conductive layer 29 is formed by using a droplet dischargingmeans 28.

When a composition is discharged into one opening in the insulating film23 in forming the second conductive layer 29, air inside the opening ispushed out of the other openings. With such a structure where aplurality of openings is connected in an insulating film, the interiorof an opening having a complicated shape can be filled with theconductive particles without leaving a bubble.

Next, baking is performed by heat treatment or laser light irradiationand removal is also performed, and any one or a plural reaction offusing, sintering, and welding of the conductive particles is performed.

In performing heat treatment, the interior of an opening having acomplicated shape may be filled with the conductive particles withoutleaving a bubble after pushing the bubble to the outside air out of aplurality of openings.

In addition, FIG. 3C shows one example of a top view in a state afterforming the second conductive layer 29. Note that FIG. 3B corresponds toa cross-sectional view taken along a broken line A-B in FIG. 3C.

Although the number of openings is six as shown in FIG. 3C, the threeopenings are each connected in the insulating film, which can bereferred to as total two openings having a complicated shape. Ascompared with Embodiment Mode 1, a few openings are provided on aninsulating surface; however, a contact area between the first conductivelayer and the second conductive layer is larger in this embodiment mode.Needless to say that the number of openings is not limited to two anddisposition of an opening is not limited particularly.

In addition, an insulator between the minute penetrating openings 26serves as a spacer that holds a surface position of the secondconductive layer, which prevents the surface of the second conductivelayer from generating a depression. Moreover, a wiring width of thesecond conductive layer 29 can be made uniform.

In addition, this embodiment mode can be arbitrarily combined withEmbodiment Mode 1.

Embodiment Mode 3

In this embodiment mode, an example of forming a plurality of openingswith the combination of laser light and etching will be explained withreference to FIGS. 4A to 4C. Portions different from Embodiment Mode 1will be explained in detail, and portions identical with FIGS. 1A to 1Dare denoted by the same reference numerals in FIGS. 4A to 4C.

After forming an insulating film made of a material that is lighttransmitting to laser light having a pulse width of 10⁻⁴ seconds to 10⁻²seconds, an insulating film 33 having a closed pore 37 is obtained byirradiation of ultrashort pulsed laser light. When an ultrashort pulsedlaser is condensed in the insulating film, multiphoton absorption canoccur only at a condensed spot where the ultrashort pulsed laser iscondensed, a closed pore can be formed, and one penetrating opening canbe formed by moving the condensed spot. When the pulsed width of thelaser light is 10⁻⁴ seconds to 10⁻² seconds, the laser light is notabsorbed by the insulating film 33. However, when multiphoton absorptionoccurs by irradiating the insulating film 33 with laser light the pulsewidth of which is extremely short (picoseconds or femtoseconds), thelaser light can be absorbed by the insulating film 33.

Note that forming an opening by using laser, light is explained indetail in Embodiment Mode 1; therefore, only brief explanation is givenhere.

As shown in FIG. 4A, a focus of laser light is formed by an opticalsystem 15, which is formed by moving a focal position during laser lightirradiation. The closed pore 37 is formed by forming a focus of laserlight with the use of an optical system 15 and by moving a focalposition during the laser light irradiation

Next, as shown in FIG. 4B, a surface of the insulating film is etched toobtain a thin film. The insulating film above the closed pore 37 isremoved by this etching so that an opening 36 penetrating through theclosed pore 37 can be formed. An insulating film 34 having a pluralityof the penetrating openings 36 is obtained at this stage. Note that adotted line shown in FIG. 4B shows a surface of the insulating filmbefore etching.

In addition, a thin film of the insulating film may be obtained bypolishing (such as CMP) instead of etching.

Next, a second conductive layer 39 is formed by discharging acomposition containing conductive particles so as to overlap with aplurality of the penetrating openings 36 with the use of a dropletdischarging method (see FIG. 4C). The second conductive layer 39 isformed by using a droplet discharging means 38.

Then, baking is performed by heat treatment or laser light irradiationand removal is also performed, and any one or a plural reaction offusing, sintering, and welding of the conductive particles is performed.

According to this embodiment mode, the penetrating opening having acomparatively shallow depth can be formed in the insulating film.

In addition, this embodiment mode can be arbitrarily combined withEmbodiment Mode 1 or Embodiment Mode 2.

Embodiment Mode 4

In this embodiment mode, an example different from Embodiment Mode 1 ina cross-sectional shape will be shown in FIGS. 5A to 5C. Portionsdifferent from Embodiment Mode 1 will be explained in detail, andportions identical with FIGS. 1A to 1D are denoted by the same referencenumerals in FIGS. 5A to 5C.

In this embodiment mode, an example in which a cross-sectional shape ofan opening is curved is shown.

First, as well as in Embodiment Mode 1, a base insulating film 11 and afirst conductive layer 12 are formed over a substrate 10 having aninsulating surface.

Next, after forming an insulating film made of a material that is lighttransmitting to laser light, an insulating film 43 having a penetratingopening 46 is obtained by irradiation of ultrashort pulsed laser light.When the pulsed width of the laser light is 10⁻⁴ seconds to 10⁻²seconds, the laser light is not absorbed by the insulating film 43.However, when multiphoton absorption occurs by irradiating theinsulating film 43 with laser light the pulse width of which isextremely short (picoseconds or femtoseconds), the laser light can beabsorbed by the insulating film 43.

Note that forming an opening by using laser light is explained in detailin Embodiment Mode 1; therefore, only brief explanation is given here.

The opening 46 having a curved cross-sectional shape as shown in FIG. 5Acan be formed by moving a focal position to an X direction or a Ydirection during laser light irradiation and then moving to a 2direction and repeatedly moving again to the X direction or Y direction.

Note that a side of the first conductive layer 12 of the opening 46having a curved cross-sectional shape is exposed.

Next, a second conductive layer 49 is formed by discharging acomposition containing conductive particles so as to overlap with aplurality of the penetrating openings 46 with the use of a dropletdischarging method (see FIG. 5B). The second conductive layer 49 isformed by using a droplet discharging means 48. In this embodiment mode,a cross-sectional shape of the opening is curved; therefore, theinterior of the opening can be filled smoothly with the compositioncontaining conductive particles.

Then, baking is performed by heat treatment or laser light irradiationand removal is also performed, and any one or a plural reaction offusing, sintering, and welding of the conductive particles is performed.

In addition, FIG. 5C shows one example of a top view in a state afterforming the second conductive layer 49. Note that FIG. 5B corresponds toa cross-sectional view taken along a broken line A-B in FIG. 5C.Moreover, FIG. 5C shows an example in which two kinds of openings in anelliptical shape and a circular shape are formed. In other words, threeelliptical openings and one circular opening, that is, total fouropenings are formed. Thus, according to the present invention, a varietyof openings can be formed by adjusting a focal position of laser lightarbitrarily.

According to this embodiment mode, a cross-sectional shape of thepenetrating opening 46 is curved so that the opening can be conductedelectrically with the second conductive layer 49 on the side surface ofthe first conductive layer 12. Therefore, the first conductive layer 12and the second conductive layer 49 are disposed so as not to overlapwith each other. Parasitic capacitance formed between the firstconductive layer 12 and the second conductive layer 49 can be reduced byhaving such a disposition.

In addition, this embodiment mode can be arbitrarily combined withEmbodiment Mode 1, Embodiment Mode 2, or Embodiment Mode 3.

Embodiment Mode 5

In this embodiment mode, an example of forming a TFT with the use of anopening formed by using laser light according to the present inventionis shown with reference to FIGS. 6A to 6D.

First, a base insulating film 201 is formed over a substrate 200 havingan insulating surface. As for the substrate 200 having an insulatingsurface, a light-transmitting substrate, for example, a glass substrate,a crystalline glass substrate, or a plastic substrate can be used. Asfor the plastic substrate, a plastic film substrate, for example, aplastic substrate of poly(ethylene terephthalate) (PET), poly(ethersulfone) (PES), poly(ethylene naphthalate) (PEN), polycarbonate (PC),nylon, polytheretherketone (PEEK), polysulfone (PSF), poly(ether imide)(PEI), polyarylate (PAR), poly(butylene terephthalate) (PBT), or thelike is preferable. In addition, a plastic substrate having heatresistance, for example, a plastic substrate in which a material whereinorganic particles of several nm diameters are dispersed in an organicpolymer matrix is processed in a sheet may also be used.

As for the base insulating film 201, an insulating film such as asilicon oxide film, a silicon nitride film, or a silicon oxynitride(SiO_(x)N_(y)) film is used. As a typical example of the base insulatingfilm 11, a two-layer structure in which a silicon nitride oxide film 50nm to 100 nm in thickness, deposited with the use of SiH₄, NH₃, and N₂Oas a reactive gas, and silicon oxynitride film 100 nm to 150 nm inthickness, deposited with the use of SiH₄ and N₂O as a reactive gas, arestacked is employed. In addition; a silicon nitride film (SiN film) or asilicon oxynitride film (SiN_(x)O_(y) film (X>Y)) the film thickness ofwhich is 10 nm or less is preferably used as one layer of the baseinsulating film 201. Moreover, a three-layer structure in which asilicon nitride oxide film, a silicon oxynitride film, and a siliconnitride film are sequentially stacked may also be employed. An exampleof forming the base insulating film 201 is shown here; however, the baseinsulating film 201 is not necessarily provided if not necessary.

Next, a first insulating film 202 serving as a gate insulating film isformed. As for the first insulating film 202, it is preferable to use amaterial that transmits and hardly absorbs a fundamental wave of laserlight used in the following opening process. As for the first insulatingfilm 202, an insulating film such as a silicon oxide film, a siliconnitride film, or a silicon oxynitride film is used. In addition, as forthe first insulating film 202, a film that is obtained by coating andbaking a solution containing polysilazane or a siloxane polymer, aphoto-curing organic resin film, a thermosetting organic resin film, orthe like may also be used.

Then, a semiconductor film is formed. The semiconductor film is formedwith an amorphous semiconductor film or a microcrystalline semiconductorfilm that is manufactured by a vapor-phase growth method, a sputteringmethod, or a thermal CVD method with the use of a semiconductor materialgas typified by silane and germanium. In this embodiment mode, anexample of using an amorphous silicon film as the semiconductor film isshown. In addition, as for the semiconductor film, ZnO or oxide of zincgallium indium manufactured by a sputtering method or a PLD (PulsedLaser Deposition) method may also be used; however, in that case, thegate insulating film is preferably an oxide containing aluminum ortitanium. Moreover, as for the semiconductor film, an organic materialsuch as pentacene, tetracene, thiophen oligomers, phenylenes, aphthalocyanine compound, poly acetylenes, polythiophenes, or a cyaninedye, manufactured by a coating method, a droplet discharging method, ora vapor deposition method, may also be used.

Subsequently, a conductive semiconductor film is formed. As for theconductive semiconductor film, a semiconductor film exhibiting n-type orp-type conductivity in which n-type or p-type impurities are added isused. The n-type semiconductor film may be formed by a PCVD method withthe use of a silane gas and a phosphine gas. In this embodiment mode, anexample of using a silicon film containing phosphorus is shown as theconductive semiconductor film. Note that, in the case of using anorganic material such as pentacene as the semiconductor film, acharge-transporting layer is preferably used instead of the conductivesemiconductor film and, for example, triphenyldiamine serving as ahole-transporting layer or oxadiazole serving as anelectron-transporting layer is preferably used.

Next, an island-shape semiconductor layer 207 and a conductivesemiconductor layer 206 are obtained by patterning with the use of aknown photolithography technique. Note that a mask may be formed using adroplet discharging method or a printing method (relief printing,lithography, copperplate printing, screen printing, or the like) toperform etching selectively, instead of the known photolithographytechnique.

Then, wirings 203, 204, and 209 are formed by selectively discharging acomposition containing a conductive material (Ag (silver), Au (gold), Cu(copper), W (tungsten), Al (aluminum), or the like) by a dropletdischarging method. FIG. 6A shows a state in which the compositioncontaining a conductive material is discharged from an ink-jet head 208.Note that the wirings 203, 204, and 209 are not limited to be formed bya droplet discharging method and, for example, the wirings may be formedby forming a metal film with the use of a sputtering method, forming amask, and performing etching selectively.

Subsequently, the conductive semiconductor layer and an upper portion ofthe semiconductor layer are etched with the use of the wirings 203, 204,and 209 as each a mask to expose part of the semiconductor layer. Theexposed portion of the semiconductor layer is a portion serving as achannel-forming region of a TFT.

Next, an interlayer insulating film 211 including a protective film isformed to prevent the channel-forming region from being contaminatedwith impurities. As for the protective film, silicon nitride obtained bya sputtering method or a PCVD method or a material containing siliconnitride oxide as its main component is used. Hydrogenation treatment isperformed in this embodiment mode after forming the protective film. Inaddition, as for the interlayer insulating film, a resin material suchas epoxy resin, acrylic resin, phenol resin, novolac resin, melamineresin, or urethane resin is used. Moreover, an organic material such asbenzocyclobutene, parylene, fluorinated-arylene-ether, or polyimidehaving transmissivity; a compound material made by polymerization of asiloxane-based polymer or the like; a composition material containing awater-soluble homopolymer and a water-soluble copolymer; or the like canbe used.

Then, a plurality of first openings 210 is formed by irradiating theinterlayer insulating film 211 including the protective film withultrashort pulsed laser light. In addition, in order to prevent thechannel-forming region from being irradiated with laser light, aplurality of second openings 212 is also formed by irradiating thebackside of the substrate as well with ultrashort pulsed laser light.FIG. 6B shows across-sectional view in which the second openings 212 areformed by ultrashort pulsed laser light that passes through an opticalsystem 205.

When the pulsed width of the laser light is 10⁻⁴ seconds to 10⁻²seconds, the laser light is not absorbed by the interlayer insulatingfilm 211 including the protective film. However, when multiphotonabsorption occurs by irradiating the interlayer insulating film 211including the protective film with laser light the pulse width of whichis extremely short (picoseconds or femtoseconds), the laser light can beabsorbed by the interlayer insulating film 211 including the protectivefilm.

Note that forming an opening by using laser light is explained in detailin Embodiment Mode 1; therefore, only brief explanation is given here.

In this embodiment mode, the first insulating film 202 between thesecond opening 212 and the semiconductor layer 207 serves as a gateinsulating film. Therefore, the film thickness of the gate insulatingfilm can be determined arbitrarily by the formation of the secondopening 212.

Subsequently, a composition containing conductive particles isdischarged with the use of a droplet discharging method to fill eachopening with the conductive particles so as to overlap with a pluralityof the penetrating first openings and second openings. Then, theconductive particles are fused and aggregated to have a crystal ofapproximately 100 nm when baking is performed; thus, a gate electrode,gate wirings 214 and 215, and a connection wiring 213 are formed (seeFIG. 6C). In this embodiment mode, the gate electrode and gate wiringsdisposed in different layers can be formed simultaneously and with thesame material.

A channel etch TFT is completed at this stage. A significant feature ofthis embodiment mode is the process order in which the gate electrode isformed after forming the interlayer insulating film.

FIG. 6D shows one example of a top view of a TFT at the stage of FIG.6C. In FIG. 6D, a cross section taken along a broken line A-Bcorresponds to a cross-sectional view of FIG. 6C. Note thatcorresponding portions are denoted by the same reference numerals.

FIG. 6D shows a double-gate TFT having two channel-forming regions. Thegate wirings 214 and 215 are electrically connected through a thirdopening 216 formed in a Z direction (a direction perpendicular to thesubstrate) and the second opening 212 formed in a Y direction. Note thatthe third opening 216 is formed using laser light in the same manner asthe first opening or the second opening.

In addition, the second opening 212 and the third opening 216 areconnected in the interlayer insulating film. Moreover, the third opening216 differs from the first openings 210 in depth. Further, theconnection wiring 213 is electrically connected to a wiring 209 throughthe first openings 210.

In addition, in this embodiment mode, the formation order of the firstopening and the second opening is not particularly limited and thesecond opening may be formed first. Moreover, the third opening may befanned by continuously moving a focal position of laser light in formingthe second opening.

In addition, an active matrix liquid crystal display device can bemanufactured with the use of the connection wiring 213 as a pixelelectrode. Moreover, an active matrix light-emitting display device canalso be manufactured by forming a first electrode overlapping theconnection wiring 213 and a partition covering a first end and stackinga layer containing an organic compound and a second electrode over thefirst electrode.

According to this embodiment mode, since a gate electrode is formedsubsequently, a semiconductor layer 207 can be formed over a flatinsulating surface; thus, an opening for forming the gate electrode canbe formed without causing damage to the semiconductor layer. Therefore,the semiconductor layer can be formed by a coating method, which iseffective in using an organic material for the semiconductor layer.

In addition, according to this embodiment mode, since the opening isformed by laser light, the comparatively low number of manufacturingprocesses of a TFT can be realized.

In addition, this embodiment mode can be arbitrarily combined withEmbodiment Mode 1, Embodiment Mode 2, Embodiment Mode 3, or EmbodimentMode 4.

Embodiment Mode 6

In this embodiment mode, an example of forming a TFT different from thatof Embodiment Mode 5 is shown with reference to FIGS. 7A to 7D.

First, a base insulating film 301 is formed over a substrate 300 havingan insulating surface. As for the substrate 300 having an insulatingsurface, a light-transmitting substrate, for example, a glass substrate,a crystalline glass substrate, or a plastic substrate can be used. Whenan opening is formed without laser light passing through the substratein the following process, a semiconductor substrate, a metal substrate,or the like can be used.

As for the base insulating film 301, an insulating film such as asilicon oxide film, a silicon nitride film, or a silicon oxynitride(SiO_(x)N_(y)) film is used.

Next, a semiconductor layer is formed over the base insulating film 301.The semiconductor layer is formed by depositing a semiconductor filmhaving an amorphous structure by a known means (a sputtering method, anLPCVD method, a plasma CVD method, or the like), then forming a resistfilm over a crystalline semiconductor film obtained by performing knowncrystallization treatment (a laser crystallization method, a thermalcrystallization method, a thermal crystallization method using acatalyst such as nickel, or the like), and then pattering it into adesired shape with the use of a first resist mask which is exposed byscanning laser light. This semiconductor layer is formed to have athickness of 25 nm to 80 nm (preferably, 30 nm to 70 nm). A material ofthe crystalline semiconductor film is not limited; however, silicon or asilicon germanium (SiGe) alloy is preferably used to form thecrystalline semiconductor film.

Then, a gate insulating film 303 covering the semiconductor layer isformed after removing the first resist mask. The gate insulating film303 is formed to have a thickness of 1 nm to 200 nm with the use of aplasma CVD method, a sputtering method, or a thermal oxidation method.As for the gate insulating film 303, a film formed of an insulating filmsuch as a silicon oxide film, a silicon nitride film, or a siliconoxynitride film is formed.

Subsequently, a second resist mask to which light exposure is performedby scanning laser light is formed after forming a resist film over thegate insulating film 303. As for the second resist mask, an impurityelement imparting p-type or n-type conductivity is selectively added tothe semiconductor layer by using an ion doping method or an ionimplantation method. Accordingly, regions where the impurity element isadded serve as impurity regions 304, 306, and 307. In addition, a region302 covered with the second resist mask where the impurity element isnot added serves as a channel-forming region of a TFT.

Thereafter, the second resist mask is removed and the impurity elementadded to the semiconductor layer is activated and hydrogenated.

Next, as shown in FIG. 7A, an interlayer insulating film 319 havingplanarity is formed. As for the interlayer insulating film 319, alight-transmitting inorganic material (silicon oxide, silicon nitride,silicon oxynitride, or the like), a photosensitive or non-photosensitiveorganic material (polyimide, acrylic, polyamide, polyimide amide,resist, or benzocyclobutene), a stack of these materials, or the like isused. Moreover, as for another light-transmitting film used for theinterlayer insulating film 319, an insulating film formed of an SiO_(x)film containing an alkyl group, obtained by a coating method, forexample, an insulating film formed using silica glass, an alkyl siloxanepolymer, an alkyl silsesquioxane polymer, a hydrogenated silsesquioxanepolymer, a hydrogenated alkyl silsesquioxane polymer, or the like can beused. As one example of a siloxane-based polymer, a coating material foran insulating film such as #PSB-K1 and #PSB-K31 manufactured by TorayIndustries, Inc., and a coating material for an insulating film such as#ZRS-5PH manufactured by Catalysts & Chemicals Industries Co., Ltd. canbe given.

Then, a plurality of first openings 309 are formed in the interlayerinsulating film 319 and the gate insulating film 303 with the use oflaser light. The plurality of first openings 309 is formed to reach theimpurity regions 304 and 307. In addition, a plurality of secondopenings 310 and 311 is formed in the interlayer insulating film 319with the use of laser light. The plurality of second openings 310 and311 is formed so as to overlap with the position of the regions 302where the impurity element is not added. FIG. 7B shows a cross-sectionalview where a focal position of ultrashort pulsed laser light is movedafter forming the second opening 310 to form the first opening 309 bythe ultrashort pulsed laser light that passes through an optical system305.

When the pulsed width of the laser light is 10⁻⁴ seconds to 10⁻²seconds, the laser light is not absorbed by the interlayer insulatingfilm 319 including the protective film. However, when multiphotonabsorption occurs by irradiating the interlayer insulating film 319including the protective film with laser light the pulse width of whichis extremely short (picoseconds or femtoseconds), the laser light can beabsorbed by the interlayer insulating film 319 including the protectivefilm.

Note that forming an opening by using laser light is explained in detailin Embodiment Mode 1; therefore, only brief explanation is given here.

Subsequently, a composition containing conductive particles of 3 nm to 7nm is discharged with the use of a droplet discharging method to filleach opening with the conductive particles so as to overlap with aplurality of the penetrating first openings and second openings. Then,the conductive particles are fused and aggregated to have a crystal ofapproximately 100 nm when baking is performed; thus, gate electrodes 313and 314, and source or drain electrodes 312 and 315 are formed (see FIG.7C). In this embodiment mode, a gate electrode and a source electrodedisposed in different layers can be formed with the same material. FIG.7C shows a state in which a composition containing a conductive materialis discharged from the ink-jet head 308.

A top gate TFT is completed at this stage. FIG. 7C shows a double gatehaving two channel-forming regions. A significant feature of thisembodiment mode is process order in which the gate electrode is formedafter forming the interlayer insulating film.

FIG. 7D) shows one example of a TFT taken along in a different crosssection from FIG. 7C. In FIG. 7C, a cross-sectional view taken along ina cross section including a broken line C-D corresponds to FIG. 7D. Notethat corresponding portions are denoted by the same reference numerals.

As shown in FIG. 7D, the second opening 310 is extended inside theinterlayer insulating film 319, and the bottom of the second opening 310is in contact with the gate insulating film 303.

In addition, although not shown here, the gate electrodes 313 and 314are in one wiring over the interlayer insulating film 319.

In addition, an active matrix liquid crystal display device can bemanufactured with the use of the TFT shown in this embodiment mode as aswitching element.

Hereinafter, a method for manufacturing a liquid crystal display devicewith the use of the TFT shown in this embodiment mode as a switchingelement is shown.

An insulating film 316 is formed after forming the source or drainelectrode 315 (FIG. 8). Then, a contact hole is formed in the insulatingfilm 316 to form a pixel electrode 317 with ITO or the like. Inaddition, a terminal electrode is formed with ITO or the like over theinsulating film 316.

Next, an alignment film 320 is formed so as to cover the pixel electrode317. Note that the alignment film 320 is preferably formed using adroplet discharging method, a screen printing method, or an offsetprinting method. Thereafter, rubbing treatment is performed to thesurface of the alignment film 320.

In addition, an opposite substrate 323 is provided with an oppositeelectrode 324 formed with a transparent electrode and an alignment film322 thereover. A sealant (not shown) with a closed pattern is thenformed by a droplet discharge method so as to surround a regionoverlapped with a pixel portion. Here, an example of drawing a sealantwith a closed pattern is shown in order to drop a liquid crystal. A dipcoating method (pumping up method) by which a liquid crystal is injectedby using capillary phenomenon may be used after providing a seal patternhaving an opening and attaching the TFT substrate and an oppositesubstrate.

Then, a liquid crystal is dropped under reduced pressure so as toprevent bubbles from entering, and the both substrates are attachedtogether. A liquid crystal is dropped once or several times in theclosed-loop seal pattern. A twisted nematic (TN) mode is mostly used asan alignment mode of a liquid crystal. In this TN mode, the alignmentdirection of liquid crystal molecules is twisted at 90° according to thepolarization of light from its entrance to the exit. In the case ofmanufacturing a liquid crystal display device of TN mode, the substratesare attached together so that the rubbing directions are crossed eachother.

Note that the space between the pair of substrates may be maintained byspraying a spherical spacer, forming a columnar spacer comprising resin,or mixing a filler into the sealant. The above columnar spacer is formedof an organic resin material mainly containing at least one material ofacrylic, polyimide, polyimide amide, and epoxy; any one material ofsilicon oxide, silicon nitride, and silicon oxynitride; or an inorganicmaterial composed of a film stack of these materials.

Subsequently, an unnecessary substrate is divided. In the case ofobtaining a plurality of panels from one substrate, each panel isseparated off. In the case of obtaining one panel from one substrate,the separation step can be skipped by attaching an opposite substratewhich is cut in advance.

Then, an FPC is attached to the terminal electrode with an anisotropicconductive layer therebetween by a known method. A liquid crystal moduleis completed according to the foregoing processes (FIG. 8). In addition,an optical film such as a color filter is attached, if necessary. In thecase of a transmissive liquid crystal display device, polarizationplates are respectively attached to both an active matrix substrate andan opposite substrate.

In addition, an active matrix light-emitting device can be manufacturedwith the use of the TFT shown in this embodiment mode.

Hereinafter, a method for manufacturing an active matrix light-emittingdisplay device with the use of the TFT shown in this embodiment mode isshown. Herein, an example where the TFT is an n-channel TFT is shown.

An insulating film 316 is formed after forming a source or drainelectrode 315. Then, a contact hole is formed in the insulating film 316to form a first electrode 318.

It is preferable that the first electrode 318 serves as a cathode. Inthe case of passing light through the first electrode 318, the firstelectrode 318 is formed by forming a predetermined pattern made from acomposition containing indium tin oxide (ITO), indium tin oxidecontaining silicon oxide (ITSO), zinc oxide (ZnO), tin oxide (SnO₂), orthe like. In addition, in the case of reflecting light by the firstelectrode 318, the first electrode 318 is formed by forming apredetermined pattern made from a composition containing metal particlesas its main component such as Ag (silver), Au (gold), Cu (copper), W(tungsten), or Al (aluminum).

Next, a partition 331 for covering the periphery of the first electrode318 is formed. The partition 331 (also referred to as a bank) is formedusing a material containing silicon, an organic material, and a compoundmaterial. Further, a porous film can also be used for the partition 331.The partition 331 is preferably formed by a photosensitive or anon-photosensitive material such as acrylic or polyimide, because thepartition 331 is formed to have a curved edge portion having a radius ofcurvature varying continuously, and an upper thin film of the partition331 can be formed without step cut.

Then, a layer serving as an electroluminescent layer, that is, a layercontaining an organic compound 330 is formed. The layer containing anorganic compound 330 has a layered structure in which each layer isformed by a vapor deposition method or a coating method. For example, anelectron-transporting layer (electron-injecting layer), a light-emittinglayer, a hole-transporting layer, and a hole-injecting layer aresequentially stacked over a cathode.

Before forming the layer containing an organic compound 330, plasmatreatment in the presence of oxygen or heat treatment in vacuumatmosphere is preferably performed. In the case of using a vapordeposition method, an organic compound is vaporized by resistanceheating in advance, and scattered toward a substrate by opening ashutter in depositing the organic compound. The vaporized organiccompound is scattered upward and deposited over a substrate through anopening portion provided to a metal mask. In order to obtain full colordisplay, alignment of a mask is preferably performed per emission color(R, G and B).

Alternatively, full color display can be obtained by using a materialexhibiting a monochromatic emission as the layer containing an organiccompound 330, and combining a color filter or color conversion layerwithout being coated separately.

Subsequently, a second electrode 332 is formed. The second electrode 332serving as an anode of the light-emitting element is formed using atransparent conductive film, which can transmit a light, for example, byITO, ITSO, or mixture of indium oxide mixed with zinc oxide (ZnO). Thelight-emitting element has the structure in which the layer containingan organic compound 330 is interposed between the first electrode andthe second electrode. Note that a material for the first electrode andthe second electrode should be selected in consideration of a workfunction. Either the first electrode or the second electrode is capableof being an anode or a cathode according to a pixel structure.

In addition, a protective layer for protecting the second electrode 332may be formed.

Next, a sealing substrate 334 is attached by a sealant (not shown) toseal the light-emitting element. Note that the region surrounded by thesealant is filled with a transparent filler 333. The filler 333 is notparticularly limited. Any material can be used as long as it alight-transmitting material, and typically, ultraviolet curable orthermosetting epoxy resin is used.

Lastly, the FPC is attached to the terminal electrode by an anisotropicconductive film in accordance with a known method.

According to the foregoing processes, an active matrix light-emittingdevice as shown in FIG. 9 can be manufactured.

In addition, this embodiment mode can be arbitrarily combined withEmbodiment Mode 1, Embodiment Mode 2, Embodiment Mode 3, Embodiment Mode4, or Embodiment Mode 5.

Embodiments of the present invention composed of the foregoing aspectsare described in further detail below.

Embodiment 1

In this embodiment, a step of forming a multilayer wiring over asemiconductor substrate will be explained with reference to FIGS. 12A to12D.

First, a semiconductor substrate 500 made of single crystal silicon isprepared (FIG. 12A). The semiconductor substrate 500 is a single crystalsilicon substrate or a compound semiconductor substrate, and typically,an N-type or a P-type single crystal silicon substrate, a GaAssubstrate, an InP substrate, a GaN substrate, an SiC substrate, asapphire substrate, or a ZnSe substrate.

Next, an n-well is selectively formed in a first element-forming regionin a main surface (also referred to as an element-forming surface or acircuit-forming surface) of the silicon substrate and a p-well isselectively formed in a second element-forming region in the samesurface, respectively.

Then, field oxide films 503, 504, and 505 to be element-isolatingregions for partitioning the first element-forming region and the secondelement-forming region are formed. The field oxide films 503, 504, and505 are thick thermal oxide films and may be formed by a known LOCOSmethod. Note that the element-isolating method is not limited to theLOCOS method. For example, the element-isolating region may have atrench structure by using a trench-isolating method, or the LOCOSstructure and the trench structure may be combined.

Subsequently, a gate insulating film is formed by, for example,thermally oxidizing the surface of the silicon substrate. The gateinsulating film may also be formed using a CVD method. A siliconoxynitride film, a silicon oxide film, a silicon nitride film, or astack thereof may be used. For example, a film stack of a silicon oxidefilm with a thickness of 5 nm which is obtained by thermal oxidation anda silicon oxynitride film with a thickness of 10 nm to 15 nm which isobtained by a CVD method is formed.

Next, a film stack of a polysilicon layer and a silicide layer areformed over the entire surface, and the film stack is patterned by alithography technique and a dry etching technique so as to form a gateelectrode 506 having a polycide structure over the gate insulating film.The polysilicon layer may be doped with phosphorus (P) at aconcentration of approximately 10²¹/cm³ in advance in order to reducethe resistance. Alternatively, high concentration n-type impurities maybe diffused after forming the polysilicon layer. Further, the silicidelayer is preferably formed of a material such as molybdenum silicide(MoSi_(x)), tungsten silicide (WSi_(x)), tantalum silicide (TaSi_(x)),or titanium silicide (TiSi_(x)) using a known method.

Then, the gate insulating film is selectively removed. Accordingly, agate insulating film 508 having a width of the gate electrode is formed.

Subsequently, sidewalls 510 to 513 are formed on the side walls of thegate electrode. For example, an insulating material layer formed ofsilicon oxide may be deposited over the entire surface by a CVD methodand the insulating material layer is preferably etched back to form thesidewalls.

Next, an ion implantation is performed into the exposed siliconsubstrate to form a source region and a drain region. Since this is thecase of manufacturing a CMOS, the first element-forming region forforming a p-channel FET is coated with a resist material, and arsenic(As) or phosphorus (P) which is an n-type impurity is injected into thesilicon substrate to form a source region 514 and a drain region 515. Atthe same time, low-concentration impurity regions 518 and 519 added withan n-type impurity by passing through the sidewalls are formed. Inaddition, the second element-forming region for forming an n-channel FETis coated with a resist material, and boron (B) which is a p-typeimpurity is injected into the silicon substrate to form a source region516 and a drain region 517. At the same time, low-concentration impurityregions 520 and 521 added with a p-type impurity by passing through thesidewalls are formed.

Then, activation treatment is performed using a GRTA method, an LRTAmethod, or the like in order to activate the ion-implanted impuritiesand to reduce crystal defects in the silicon substrate, which isgenerated by the ion implantation (see FIG. 12A).

Subsequently, as shown in FIG. 12B, a first interlayer insulating film545 is formed. The first interlayer insulating film 545 is formed in athickness of 100 nm to 2000 nm with a silicon oxide film, a siliconoxynitride film, or the like by a plasma CVD method or a low-pressureCVD method. Further, an interlayer insulating film formed ofphosphosilicate glass (PSG), borosilicate glass (BSG), orborophosphosilicate glass (PBSG) may be stacked thereover.

Next, as shown in FIG. 12B, penetrating openings 541 to 544 are formedby irradiation of laser light emitted from an ultrashort pulsed laser.This is a method for forming an opening according to the presentinvention shown in Embodiment Mode 1.

Then, as shown in FIG. 12C, conductive films 551 to 554 are formed bydischarging and baking a composition containing conductive particles tothe openings by a droplet discharging method. According to the presentinvention, a depression is not generated in portions overlapping withthe openings; thus, top surfaces of the conductive films 551 to 554 arealmost in one plane.

Thereafter, a second interlayer insulating film 561 is formed. Then,openings and conductive films 562 to 565 are formed in the same manner,and multilayer wirings can be formed as shown in FIG. 12D. Since the topsurfaces of the conductive films 551 to 554 are almost in one plane, thedepth of each of the openings penetrating through the second interlayerinsulating film 561 can be kept uniform.

In addition, an SOT substrate is used as the semiconductor substrate 500and treatment in which a circuit having a MOS transistor can be peeledat an interface with an oxidized insulating film or in the layer thereofor at an interface between the oxidized insulating film and a siliconsubstrate or at an interface between the oxidized insulating film andthe circuit is performed. Therefore, the circuit having a MOS transistorcan be peeled. In addition, a thinner film of a semiconductor device canbe obtained by attaching the peeled circuit having a MOS transistor to aflexible substrate.

In addition, the semiconductor device shown in this embodiment isapplicable to various semiconductor devices such as a bipolar transistoras well as a MOS transistor. Moreover, the semiconductor device is alsoapplicable to an electric circuit such as a memory circuit or a logiccircuit.

An IC chip in which an FET manufactured according to this embodiment isintegrated can be used as a thin film integrated circuit or anon-contact thin film integrated circuit device (also referred to as awireless IC tag or RFID (Radio Frequency Identification)).

FIG. 13 shows an example of an ID card in which an IC chip 1516according to the present invention is attached to a card-like substrate1518 provided with a conductive layer 1517 serving as an antenna. Theconductive layer 1517 serving as an antenna can also be formed by adroplet discharging method. In addition, a contact hole with aconnection electrode connected to the conductive layer 1517 serving asan antenna may be formed using a technique for forming an opening byusing laser light. Thus, the IC chip 1516 according to the presentinvention is small, thin, and lightweight, so that diverse uses can berealized and the design of an article is not spoiled even when the ICchip is attached to the article.

Note that the IC chip 1516 according to the present invention is notlimited to the case of being attached to the card-like substrate 1518,and can be attached to an article having a curved surface or variousshapes. For example, the IC chips can be used in bill, money, coin,securities, bearer bonds, certificates (such as a driver's license, or aresident's card, packing cases (such as a wrapper or a bottle), memorymedia (such as a DVD, a video tape), vehicles (such as a bicycle),belongings (such as a bag, or glasses), food, clothing, commodities, andthe like.

In addition, this embodiment can be arbitrarily combined with EmbodimentMode 1, Embodiment Mode 2, Embodiment Mode 3, Embodiment Mode 4,Embodiment Mode 5, or Embodiment Mode 6.

Embodiment 2

In this embodiment, a module having the display panel shown in the aboveEmbodiment Mode 5 or Embodiment Mode 6 will be explained with referenceto FIG. 14, FIG. 14 shows a module including a display panel 9501 and acircuit board 9502. For example, a control circuit 9504, a signaldivision circuit 9505, and the like are mounted on the circuit board9502. In addition, the display panel 9501 is connected to the circuitboard 9502 through a connecting wire 9503. As for the display panel9501, the liquid crystal panel or the light-emitting display panel shownin Embodiment Mode 5 or Embodiment Mode 6 may be arbitrarily used.

The display panel 9501 has a pixel portion 9506 where a light-emittingelement is provided in each pixel, a scanning-line driver circuit 9507,and a signal-line driver circuit 9508 that supplies a video signal to aselected pixel. The pixel portion 9506 has the same structure as thatshown in Embodiment Mode 5 or Embodiment Mode 6. As for thescanning-line driver circuit 9507 and the signal-line driver circuit9508, IC chips are mounted on the substrate by a known mounting methodsuch as a method using an anisotropic conductive adhesive or ananisotropic conductive film, a COG method, a wire bonding method, reflowtreatment using a solder bump, or the like.

This embodiment allows a display module to be formed at low cost.

In addition, this embodiment can be arbitrarily combined with EmbodimentMode 1, Embodiment Mode 2, Embodiment Mode 3, Embodiment Mode 4,Embodiment Mode 5, Embodiment Mode 6, or Embodiment 1.

Embodiment 3

Although a liquid crystal display module and a light-emitting displaymodule are shown as an example of the display module in the aboveembodiment, the present invention is not limited thereto. The presentinvention can be appropriately applied in forming an opening and wiringof a display module such as a DMD (Digital Micro mirror Device), a PDP(Plasma Display Panel), an FED (Field Emission Display), anelectrophoretic display device (electronic paper), or an electrodeposition image display device.

In addition, this embodiment can be arbitrarily combined with EmbodimentMode 1, Embodiment Mode 2, Embodiment Mode 3, Embodiment Mode 4,Embodiment Mode 5, or Embodiment Mode 6.

Embodiment 4

The semiconductor device shown in the above embodiment modes andembodiments may be applied to electronic apparatuses such as atelevision set (also simply referred to as a television or a televisionreceiver). Here, a specific example of a television set will beexplained with reference to FIGS. 15A and 15B.

FIG. 15A shows a block diagram of a television set, while FIG. 15B showsa perspective view of a television set. A liquid crystal television setand an EL television set can be completed by using the liquid crystalmodule and the EL module that are shown in the above embodiments.

FIG. 15A is a block diagram showing main components of a television set.A tuner 9511 receives a video signal and an audio signal. The videosignal is processed by an image detection circuit 9512, a video signalprocessing circuit 9513 that converts a signal outputted from the imagedetection circuit into a color signal corresponding to each of red,green, and blue, and a control circuit 9514 that converts the videosignal in accordance with input specifications of a driver IC. Thecontrol circuit 9514 outputs a signal to a scanning-line driver circuit9516 and a signal-line driver circuit 9517 of a display panel 9515. Inthe case of digital driving, a signal division circuit 9518 may beprovided on the signal line side, so that an inputted digital signal isdivided into m signals to be supplied.

Among signals received by the tuner 9511, an audio signal is transmittedto a sound detection circuit 9521, and an output thereof is supplied toa speaker 9523 through an audio signal processing circuit 9522. Acontrol circuit 9524 receives control information of a receiving station(received frequency) and a sound volume from an input portion 9525, andtransmits signals to the tuner 9511 and the audio signal processingcircuit 9522.

As shown in FIG. 15B, a television set can be completed by incorporatinga module in a housing 9531. A display screen 9532 is formed using amodule typified by a liquid crystal module and an EL module. Inaddition, the television set also includes a speaker 9533, operatingswitches 9534, and the like.

Since this television set includes the display panel 9515, costreduction thereof can be achieved. In addition, the television set withhigh definition can be provided.

The application of the present invention is not limited to thetelevision receiver, and various applications are possible, such as amonitor for a personal computer as well as, in particular, a displaymedium with a large area such as an information display panel atstations or airports, and an advertisement display panel on the street.

In addition, this embodiment can be arbitrarily combined with EmbodimentMode 1, Embodiment Mode 2, Embodiment Mode 3, Embodiment Mode 4,Embodiment Mode 5, or Embodiment Mode 6.

Embodiment 5

A semiconductor device and an electronic device according to the presentinvention include a camera such as a video camera or a digital camera, agoggle type display (head mounted display), a navigation system, anaudio player (a car audio, an audio component, and the like), a personalcomputer, a game machine, a portable information terminal (a mobilecomputer, a cellular phone, a portable game machine, an electronic book,and the like), an image reproducing device provided with a recordingmedium (specifically a device capable of reproducing the content of arecording medium such as a Digital Versatile Disc (DVD) and that has adisplay device capable of displaying the image), and the like. Specificexamples of the electronic devices are shown in FIGS. 16A to 16E.

FIG. 16A is a digital camera, which includes a main body 2101, a displayportion 2102, an imaging portion, operation keys 2104, a shutter 2106,and the like. Note that FIG. 16A is viewed from the side of the displayportion 2102 and the imaging portion is not shown. According to thepresent invention, the digital camera can be obtained through a processhere the manufacturing cost is reduced.

FIG. 16B is a personal computer, which includes a main body 2201, ahousing 2202, a display portion 2203, a keyboard 2204, an externalconnection port 2205, a pointing mouse 2206, and the like. According tothe present invention, the personal computer can be obtained through aprocess where the manufacturing cost is reduced.

FIG. 16C is a mobile image reproducing device provided with a recordingmedium (specifically, a DVD player), which includes a main body 2401, ahousing 2402, a display portion A 2403, a display portion B 2404, arecording medium (DVD or the like) reading portion 2405, operation keys2406, a speaker portion 2407, and the like. The display portion A 2403is used mainly for displaying image information, whereas the displayportion B 2404 is used mainly for displaying text information. Note thatthe image reproducing device provided with a recording medium alsoincludes a home-use game machine or the like. According to the presentinvention, the image reproducing device can be obtained through aprocess where the manufacturing cost is reduced.

In addition, FIG. 16D is a perspective view of a portable informationterminal, and FIG. 16E is a perspective view showing a state of using itas a folding cellular phone. In FIG. 16D, users operate operation keys2706 a with their right fingers and operate operation keys 2706 b withtheir left fingers when they are used as a keyboard. According to thepresent invention, the portable information terminal can be obtainedthrough a process where a manufacturing cost is reduced.

As shown in FIG. 16E, in folding a cellular phone, users have a mainbody 2701 and a housing 2702 in one hand and use an audio input portion2704, an audio output portion 2705, operation keys 2706 c, an antenna2708, and the like.

The portable information terminals shown in FIGS. 16D and 16E eachincludes a high-definition display portion 2703 a which horizontallydisplays images and characters mainly and a display portion 2703 b whichvertically displays.

As described above, various electronic devices can be completed byemploying a manufacturing method or a structure according to the presentinvention, that is, any one of Embodiment Modes 1, Embodiment Mode 2,Embodiment Mode 3, Embodiment Mode 4, Embodiment Mode 5, Embodiment Mode6, and Embodiments 1 to 4.

Embodiment 6

According to the present invention, a semiconductor device serving as awireless chip (also called a wireless processor, a wireless memory, or awireless tag) can be manufactured.

An example of mounting a chip obtained by cutting a semiconductorsubstrate on a card having an antenna is shown in Embodiment 1; however,a wireless chip can also be formed using a TFT.

A structure of a wireless chip according to the present invention willbe explained with reference to FIG. 17. A wireless chip is constitutedby a thin film integrated circuit 9303 and an antenna 9304 connectedthereto. The thin film integrated circuit 9303 and the antenna 9304 aresandwiched between cover materials 9301 and 9302. The thin filmintegrated circuit 9303 may be attached to the cover materials with anadhesive. In FIG. 17, one surface of the thin film integrated circuit9303 is attached to the cover material 9301 with an adhesive 9305.

The thin film integrated circuit 9303 is formed using a TFT shown inEmbodiment Mode 5 or Embodiment Mode 6, then peeled off by a knownpeeling step and attached to a cover material. In addition, thesemiconductor element used for the thin film integrated circuit 9303 isnot limited thereto, and in addition to the TFT, a memory element, adiode, a photoelectric converter, a resistor, a coil, a capacitor, aninductor, or the like may be used.

As shown in FIG. 17, an interlayer insulating film 9311 is formed overthe TFT of the thin film integrated circuit 9303, and the antenna 9304is connected to the TFT through the interlayer insulating film 9311. Inaddition, a barrier film 9312 made of silicon nitride or the like isformed over the interlayer insulating film 9311 and the antenna 9304.

The antenna 9304 is formed by discharging a droplet containing aconductor such as gold, silver and copper by a droplet dischargingmethod, then baking and drying it. When the antenna is formed by adroplet discharging method, reduction in the number of steps can berealized; leading to cost reduction.

Each of the cover materials 9301 and 9302 preferably uses a film (madeof polypropylene, polyester, vinyl, polyvinyl fluoride, vinyl chloride,or the like), paper of a fibrous material, a film where a base film(polyester, polyamide, an inorganic vapor deposition film, papers, orthe like), and an adhesive synthetic resin film (an acrylic basedsynthetic resin, an epoxy based synthetic resin, or the like) arestacked, or the like. The film is obtained by performing sealingtreatment to the subject by thermocompression. In the sealing treatment,an adhesive layer formed on the upper most surface of the film or alayer (not an adhesive layer) formed on the outermost layer is melted byheat treatment to adhere by applying pressure.

When the cover materials use a flammable pollution-free material such aspaper, fiber and carbon graphite, the used wireless chip can be burnedor cut out. In addition, the wireless chip using such a material ispollution free because it does not generate poison gas even if beingburned.

Although the wireless chip is attached to the cover material 9301 withthe adhesive 9305 in FIG. 17, the wireless chip may be attached to theobject instead of the cover material 9301.

The wireless chip 9210 may be mounted on various objects and one exampleis shown in FIG. 18A to 18F, for example, such as bills, coins,securities, bearer bonds, certificates (licenses, resident cards and thelike, see FIG. 18A), containers for wrapping objects (wrapping papers,bottles and the like, see FIG. 18C), recording media (DVDs, video tapesand the like, see FIG. 18B), vehicles (bicycles and the like, see FIG.18D), belongings (bags, glasses and the like), foods, plants, animals,human body, clothes, living ware, and electronic apparatuses, orshipping tags of objects (see FIGS. 18E and 18F). The electronicapparatuses include liquid crystal display devices, EL display devices,television sets (also simply called televisions or televisionreceivers), cellular phones, and the like.

A wireless chip is attached to the surface of the object or incorporatedin the object to be fixed. For example, a wireless chip is preferablyincorporated in a paper of a book, or an organic resin of a package.When a wireless chip is incorporated in bills, coins, securities, bearerbonds, certificates, and the like, forgery thereof can be prevented. Inaddition, when a wireless chip is incorporated in containers forwrapping objects, recording media, belongings, foods, clothes,livingware, electronic apparatuses, and the like, test systems, rentalsystems, and the like can be performed more efficiently. A wireless chipaccording to the present invention is obtained in such a manner that athin film integrated circuit formed over a substrate is peeled off by aknown peeling step and then attached to a cover material; therefore, thewireless chip can be reduced in size, thickness and weight and can bemounted on an object while keeping the attractive design. In addition,since such a wireless chip has flexibility, the wireless chip can beattached to an object having a curved surface, such as bottles andpipes.

When a wireless chip according to the present invention is applied toproduct management and distribution system, high performance system canbe achieved. For example, when information stored in a wireless chipmounted on a shipping tag is read by a reader/writer provided beside aconveyor belt, information such as distribution process and deliveryaddress is read to easily inspect and distribute the object.

In addition, this embodiment can be arbitrarily combined with EmbodimentMode 1, Embodiment Mode 2, Embodiment Mode 3, Embodiment Mode 4,Embodiment Mode 5, Embodiment Mode 6, or Embodiment 1.

According to the present invention, since the number of etching stepsaccompanying a photolithography method can be reduced, the loss andeffluent amount of a material solution can be reduced. In addition, thepresent invention can realize a manufacturing process with the use of adroplet discharging method suitable for manufacturing a large-sizedsubstrate in mass production.

The present application is based on Japanese Patent Application serialNo. 2005-014756 filed on Jan. 21, 2005 in Japanese Patent Office, thecontents of which are hereby incorporated by reference.

1. A semiconductor device: a first cover material; a second covermaterial; and a transistor comprising a gate electrode, a gateinsulating film, a source electrode, a drain electrode, and asemiconductor layer, the transistor being interposed between the firstcover material and the second cover material, wherein the first covermaterial and the second cover material have flexibility, and wherein thesemiconductor layer which includes a metal oxide containing indium. 2.The semiconductor device according to claim 1, wherein at least one ofthe first cover material and the second cover material is formed of alaminate film, an organic film, an inorganic film, or a resin film, or astacked film.
 3. The semiconductor device according to claim 1, whereinthe transistor is any one of a top gate transistor, a bottom gatetransistor and a forward stagger transistor.
 4. The semiconductor deviceaccording to claim 1, further comprising an antenna electricallyconnected to the transistor.
 5. An RFID comprising the semiconductordevice according to claim
 1. 6. A semiconductor device: a first covermaterial; a second cover material; and a transistor comprising a gateelectrode, a gate insulating film, a source electrode, a drainelectrode, and a semiconductor layer, the transistor being interposedbetween the first cover material and the second cover material, whereinthe first cover material and the second cover material have flexibility,and wherein the semiconductor layer which includes a metal oxidecontaining In—Ga—Zn—O.
 7. The semiconductor device according to claim 6,wherein at least one of the first cover material and the second covermaterial is formed of a laminate film, an organic film, an inorganicfilm, a resin film, or a stacked film.
 8. The semiconductor deviceaccording to claim 6, wherein the transistor is any one of a top gatetransistor, a bottom gate transistor and a forward stagger transistor.9. The semiconductor device according to claim 6, further comprising anantenna electrically connected to the transistor.
 10. An RFID comprisingthe semiconductor device according to claim
 6. 11. A semiconductordevice: a first cover material; an adhesive over the first covermaterial; a second cover material over the adhesive; a transistorinterposed between the first cover material and the second covermaterial, the transistor comprising a gate electrode, a gate insulatingfilm, and a semiconductor layer; and a conductive layer electricallyconnected to the transistor, wherein the semiconductor layer includes ametal oxide containing indium.
 12. The semiconductor device according toclaim 11, wherein at least one of the first cover material and thesecond cover material is formed of a laminate film, an organic film, aninorganic film, a resin film, or a stacked film.
 13. The semiconductordevice according to claim 11, wherein the transistor is any one of a topgate transistor, a bottom gate transistor and a forward staggertransistor.
 14. The semiconductor device according to claim 11, whereinthe conductive layer serves as an antenna.
 15. An RFID comprising thesemiconductor device according to claim
 11. 16. A semiconductor device:a first cover material; an adhesive over the first cover material; asecond cover material over the adhesive; a transistor interposed betweenthe first cover material and the second cover material, the transistorcomprising a gate electrode, a gate insulating film, and a semiconductorlayer; and a conductive layer electrically connected to the transistor,wherein the semiconductor layer includes a metal oxide containingIn—Ga—Zn—O.
 17. The semiconductor device according to claim 16, whereinat least one of the first cover material and the second cover materialis formed of a laminate film, an organic film, an inorganic film, aresin film, or a stacked film.
 18. The semiconductor device according toclaim 16, wherein the transistor is any one of a top gate transistor, abottom gate transistor and a forward stagger transistor.
 19. Thesemiconductor device according to claim 16, wherein the conductive layerserves as an antenna.
 20. An RFID comprising the semiconductor deviceaccording to claim
 16. 21. A semiconductor device: a first flexiblefilm; an adhesive over the first flexible film; a transistor over theadhesive; an insulating layer over the transistor; a conductive layerover the insulating layer, the conductive layer being electricallyconnected to the transistor; and a second flexible film over theconductive layer, wherein the transistor comprises a gate electrode, agate insulating film, and a semiconductor layer which includes a metaloxide containing indium.
 22. The semiconductor device according to claim21, wherein at least one of the first flexible film and the secondflexible film is formed of a laminate film, an organic film, aninorganic film, a resin film, or a stacked film.
 23. The semiconductordevice according to claim 21, wherein the transistor is any one of a topgate transistor, a bottom gate transistor and a forward staggertransistor.
 24. The semiconductor device according to claim 21, whereinthe conductive layer serves as an antenna.
 25. An RFID comprising thesemiconductor device according to claim
 21. 26. A semiconductor device:a first flexible film; an adhesive over the first flexible film; atransistor over the adhesive; an insulating layer over the transistor; aconductive layer over the insulating layer, the conductive layer beingelectrically connected to the transistor; and a second flexible filmover the conductive layer, wherein the transistor comprises a gateelectrode, a gate insulating film, and a semiconductor layer whichincludes a metal oxide containing In—Ga—Zn—O.
 27. The semiconductordevice according to claim 26, wherein at least one of the first flexiblefilm and the second flexible film is formed of a laminate film, anorganic film, an inorganic film, a resin film, or a stacked film. 28.The semiconductor device according to claim 26, wherein the transistoris any one of a top gate transistor, a bottom gate transistor and aforward stagger transistor.
 29. The semiconductor device according toclaim 26, wherein the conductive layer serves as an antenna.
 30. Thesemiconductor device according to claim 26, wherein each of the firstflexible film and the second flexible film includes a resin selectedfrom the group consisting of polypropylene, polyester, vinyl, polyvinylfluoride, vinyl chloride, polyimide, an acrylic based synthetic resin,and an epoxy based synthetic resin.
 31. An RFID comprising thesemiconductor device according to claim 26.